If you are using a ball bearing swivel you use a #2 and that works with 1/4oz up to 1oz. Clevis you use a #3, and for beads a 1/8" and 5/32" will both work. So a single spin 1/4oz bait I'd use either a #3.5 or #4 willow or a #3 or #3.5 Colorado. A 3/8oz single spin willow will be a #4 or #4.5 and a Colorado will be a #4 Colorado. The 1/2oz bait would be a #5 or #6 willow or the #5 Colorado. Those are single spin models, you don't need a clevis with a single spin. Tandem baits you'll need a #3 clevis for .035" and .040" diameter wire. The blade sizes are a little different, for 1/4oz baits I like a #3.5 willow and a #2 Colorado, for a 3/8oz bait I use a #4.5 willow and a #3 Colorado and the 1/2oz is a #5 willow and a #3 or a #3.5 Colorado. There is no industry standard or rule of thumb, there are charts but even those will have different recommendations for different sizes.