How to efficiently create valid polylines

'************************************************************************************************
'* GEOMETRY TYPE : POLYLINE
'* NOTE :In the following samples the geometries are simple without having to use ITopologicalOpeartor::Simplify.
'*       However if the data creation process cannot insure simple geometries
'*       the geometries have to be simplified before storing or using those in geometry operations.
'************************************************************************************************

'*************************************************************************
'* NAME : createMultipartPolylinePathSegmentCollection
'* DESCRIPTION : Create a multipart polyline using path via ISegmentCollection.
'* This sub is demonstrating it by creating a branching polyline.
'* NOTE : This is the approach to use if non-linear segments (Circular Arc, Elliptical Arc and Bezier Curve) have to be created.
'*************************************************************************

Sub createMultipartPolylinePathSegmentCollection()
    Dim pPointsPath0(1) As IPoint, pPointsPath1(1) As IPoint, pPointsPath2(1) As IPoint
    Dim pPointsPath3(1) As IPoint, pPointsPath4(1) As IPoint, pPointsPath5(1) As IPoint, pPointsPath6(1) As IPoint
    Dim pPathColl(6) As ISegmentCollection, pLine0 As ILine, pLine1 As ILine, pLine2 As ILine, pLine3 As ILine
    Dim pLine4 As ILine, pLine5 As ILine, pLine6 As ILine, i As Long, pspref As ISpatialReference, pGeoSpRef As IGeometry
    Dim pGeometry(6) As IGeometry, pPolColl As IGeometryCollection
    'Create a new polyline the IGeometryCollection interface
    Set pPolColl = New Polyline
    '*********************************************************
    'THE SPATIAL REFERENCE SHOULD BE SET HERE ON THE POLYLINE
    'Here the spatial reference is created in memory but could also come from various sources:
    'IMap, IGeodataset, IGeometry etc...
    Set pspref = New UnknownCoordinateSystem
    pspref.SetFalseOriginAndUnits -10000, -10000, 100000 'Set the false origin and units.
    'The XYUnits value is equivalent to the precision specified when creating a feature class
    Set pGeoSpRef = pPolColl
    Set pGeoSpRef.SpatialReference = pspref
    '*********************************************************
    
    'Initialize points
    For i = 0 To 1
        Set pPointsPath0(i) = New EsriGeometry.Point
        Set pPointsPath1(i) = New EsriGeometry.Point
        Set pPointsPath2(i) = New EsriGeometry.Point
        Set pPointsPath3(i) = New EsriGeometry.Point
        Set pPointsPath4(i) = New EsriGeometry.Point
        Set pPointsPath5(i) = New EsriGeometry.Point
        Set pPointsPath6(i) = New EsriGeometry.Point
    Next
    'Initialize path
    For i = 0 To 6
        Set pPathColl(i) = New Path
        Set pGeometry(i) = pPathColl(i) 'QI to IGeometry to be able to use AddGeometries later on
    Next
    'Initialize lines, putcoords of points and add each line to a separate path
    Set pLine0 = New EsriGeometry.Line
    pPointsPath0(0).PutCoords 100, 100
    pPointsPath0(1).PutCoords 100, 150
    pLine0.PutCoords pPointsPath0(0), pPointsPath0(1)
    pPathColl(0).AddSegment pLine0
    Set pLine1 = New EsriGeometry.Line
    pPointsPath1(0).PutCoords 100, 150
    pPointsPath1(1).PutCoords 100, 250
    pLine1.PutCoords pPointsPath1(0), pPointsPath1(1)
    pPathColl(1).AddSegment pLine1
    Set pLine2 = New EsriGeometry.Line
    pPointsPath2(0).PutCoords 100, 250
    pPointsPath2(1).PutCoords 75, 300
    pLine2.PutCoords pPointsPath2(0), pPointsPath2(1)
    pPathColl(2).AddSegment pLine2
    Set pLine3 = New EsriGeometry.Line
    pPointsPath3(0).PutCoords 100, 250
    pPointsPath3(1).PutCoords 150, 300
    pLine3.PutCoords pPointsPath3(0), pPointsPath3(1)
    pPathColl(3).AddSegment pLine3
    Set pLine4 = New EsriGeometry.Line
    pPointsPath4(0).PutCoords 100, 150
    pPointsPath4(1).PutCoords 100, 200
    pLine4.PutCoords pPointsPath4(0), pPointsPath4(1)
    pPathColl(4).AddSegment pLine4
    Set pLine5 = New EsriGeometry.Line
    pPointsPath5(0).PutCoords 100, 200
    pPointsPath5(1).PutCoords 150, 250
    pLine5.PutCoords pPointsPath5(0), pPointsPath5(1)
    pPathColl(5).AddSegment pLine5
    Set pLine6 = New EsriGeometry.Line
    pPointsPath6(0).PutCoords 100, 200
    pPointsPath6(1).PutCoords 150, 175
    pLine6.PutCoords pPointsPath6(0), pPointsPath6(1)
    pPathColl(6).AddSegment pLine6
    'Add all the paths to the polyline using AddGeometries method
    pPolColl.AddGeometries 7, pGeometry(0)
    'You can draw, store or use the polygon (pPolColl) in other geometry operations at this point
End Sub

'*************************************************************************
'* NAME : createMultipartPolylinePathPointCollection
'* DESCRIPTION : Create a multipart polyline using path via IPointCollection.
'* This sub is demonstrating it by creating a branching polyline.
'*************************************************************************

Sub createMultipartPolylinePathPointCollection()
    Dim pPointsPath0(1) As IPoint, pPointsPath1(1) As IPoint, pPointsPath2(1) As IPoint
    Dim pPointsPath3(1) As IPoint, pPointsPath4(1) As IPoint, pPointsPath5(1) As IPoint, pPointsPath6(1) As IPoint
    Dim pPathColl(6) As IPointCollection, i As Long, pspref As ISpatialReference, pGeoSpRef As IGeometry
    Dim pGeometry(6) As IGeometry, pPolColl As IGeometryCollection
    'Create a new polyline the IGeometryCollection interface
    Set pPolColl = New Polyline
    '*********************************************************
    'THE SPATIAL REFERENCE SHOULD BE SET HERE ON THE POLYLINE
    'Here the spatial reference is created in memory but could also come from various sources:
    'IMap, IGeodataset, IGeometry etc...
    Set pspref = New UnknownCoordinateSystem
    pspref.SetFalseOriginAndUnits -10000, -10000, 100000 'Set the false origin and units.
    'The XYUnits value is equivalent to the precision specified when creating a feature class
    Set pGeoSpRef = pPolColl
    Set pGeoSpRef.SpatialReference = pspref
    '*********************************************************
    'Initialize points
    For i = 0 To 1
        Set pPointsPath0(i) = New EsriGeometry.Point
        Set pPointsPath1(i) = New EsriGeometry.Point
        Set pPointsPath2(i) = New EsriGeometry.Point
        Set pPointsPath3(i) = New EsriGeometry.Point
        Set pPointsPath4(i) = New EsriGeometry.Point
        Set pPointsPath5(i) = New EsriGeometry.Point
        Set pPointsPath6(i) = New EsriGeometry.Point
    Next
    'Initialize path
    For i = 0 To 6
        Set pPathColl(i) = New Path
        Set pGeometry(i) = pPathColl(i) 'QI to IGeometry to be able to use AddGeometries later on
    Next
    'Putcoords on the points
    pPointsPath0(0).PutCoords 100, 100
    pPointsPath0(1).PutCoords 100, 150
    pPointsPath1(0).PutCoords 100, 150
    pPointsPath1(1).PutCoords 100, 250
    pPointsPath2(0).PutCoords 100, 250
    pPointsPath2(1).PutCoords 75, 300
    pPointsPath3(0).PutCoords 100, 250
    pPointsPath3(1).PutCoords 150, 300
    pPointsPath4(0).PutCoords 100, 150
    pPointsPath4(1).PutCoords 100, 200
    pPointsPath5(0).PutCoords 100, 200
    pPointsPath5(1).PutCoords 150, 250
    pPointsPath6(0).PutCoords 100, 200
    pPointsPath6(1).PutCoords 150, 175
    
    'Add points to separate paths
    pPathColl(0).AddPoints 2, pPointsPath0(0)
    pPathColl(1).AddPoints 2, pPointsPath1(0)
    pPathColl(2).AddPoints 2, pPointsPath2(0)
    pPathColl(3).AddPoints 2, pPointsPath3(0)
    pPathColl(4).AddPoints 2, pPointsPath4(0)
    pPathColl(5).AddPoints 2, pPointsPath5(0)
    pPathColl(6).AddPoints 2, pPointsPath6(0)
    'Add all the paths to the polyline using AddGeometries method
    pPolColl.AddGeometries 7, pGeometry(0)
    'You can draw, store or use the polygon (pPolColl) in other geometry operations at this point
End Sub