Any good icon design tutorial for BlackBerry size icons?

[ByteStackers]

Many customers have told me how happy they would be if I included custom icons in my theme. As much as I would like to do this, every time I try to create 68x68 icons, they look terrible . Does any one have any advice or tutorials on how to make good looking, small icons? Thanks!

[Heavy Fluid]

I make my icons 72x72, on a transparent 80x80 background image. This is for 480x360 devices, so if you are on a different one, try a different size more for the device, depending on the device.