How to make a Dropshadow?

How can you make a proper dropshadow for an image? I just used a gradientbrush and filled another rectangle but that doesn't look nearly as good.

VB Code:

Public Function DropShadow(ByVal img As Image, ByVal OffSet As Integer) As Bitmap
        Dim g As Graphics
        Dim bmp As New Bitmap(CType(img.Width, Integer), CType(img.Height, Integer))
        g = Graphics.FromImage(bmp)
        Dim gb As New Drawing2D.LinearGradientBrush(New RectangleF(OffSet, OffSet, img.Width, img.Height), Color.Black, Color.White, Drawing2D.LinearGradientMode.ForwardDiagonal)
        g.FillRectangle(gb, New Rectangle(OffSet, OffSet, img.Width, img.Height))
        g.DrawImage(img, New Rectangle(0, 0, img.Width, img.Height), 0, 0, img.Width + OffSet, img.Height + OffSet, GraphicsUnit.Pixel)
        Return bmp
    End Function

Never done one before...

but maybe you can get better results using a PathGradientBrush...

VB Code:

Dim cBrush As New PathGradientBrush(myPath)
Dim colors() As Color = {Color.GoldenRod}
 
cBrush.CenterColor = Color.Yellow
cBrush.SurroundColors = colors
 
Graphics.FillPath(cbrush,mypath)

I haven't used Paths yet so I'll have to check them out. Thanks for the suggestion. For now I used three small rectangles but it still doesn't look that good.