The .015 glitter is a dandy size for crappie/panfish sized baits and even some bass/walleye sized stuff. The .040 size is a bit bolder for larger baits. Small flake like .008 and .004 are hard to manipulate while you're getting started and have a limited scope of use so I'd say stay away from those for now until you find out how plastic handles and how glitter can help or wreck a batch.