For some reason that still escapes me, proper crimping tools are either A) Hard to get hold of, or B) Ridiculously expensive, and most of the time both.
Most people probably use pliers and get almost passable results.
Wire strippers make dealing with cables a lot less painful, you can get get a decent one on ebay for 10USD.
Make sure you get one that supports the wire gauge you're using, typically 20-30 AWG.
They work if you're careful, results will not be as nice as with a proper crimp tool.
Hozan P-706 Crimper
Tested with good results on:
Where to get it
Eclipse 300-035 Multi-Purpose Crimping Tool
Claim: "Crimps a variety of open barrel contacts including solderless lugs and D-sub contacts".
Tested with horrible/useless results on: