I have been so frustrated in the past when riding in wet/muddy conditions when it comes to kicking my '06 CRF450R over and just having my boot slide off the kickstart lever and the lever snaps back and gouges me in the leg. The 4-strokes tend to take a little more "leg" to get them going. This can be fixed for less than $3.
All you have to do is go to the hardware store (got mine at Ace) and buy a cable/rope clamp and Nylock nuts to match the bolt size/pitch. Measure the end of your kickstart lever before you go (or take it with you.)
Basically, install the clamp on the end of your kickstart lever with the bolt ends pointing towards the engine. Screw down with the Nylock nuts. If the bolt ends are a touch long, you can hacksaw them off to the top of the nuts. You're done! Now you have your own "Kicker Klamp."
Most bikes have plenty of room between the tip of the kickstart lever and the frame/engine. This idea should work for most...just need to get the right size cable/rope clamp. It can tend to beat on the bottom of the boot a little, but the guaranteed grip you get on your kickstart lever is priceless (at lease IMO.)