It all boils down to thinking about what you are trying to do. If you are towing a similar sized vehicle out of a ditch, mud or snow, then a snatch strap will probably be best. If you are trying to break small roots free then a chain to give a quick jerk, but expect it to fly if you jerk too hard. If you are trying to drag a heavy vehicle (or load) up an embankment, then use a winch and snatch-block. You need different equipment to do different jobs, but what ever you choose, make sure it is strong enough for the purpose and think about where it will fly if something breaks.
Unless you are trying to break something such as roots, then a smooth pull with gradually increasing force will normally do the job. This might be slowly tightening up the winch cable or quickly jerking on a 1" nylon tow rope. Either way its a smooth force being gradually applied, not jerking on a steel chain....
When using nylon make sure that you are not pulling on a sharp edge and always make sure that you are fastened to someplace solid, not steering members or a light duty trailer hitch....
If you feel that the load should be moving but doesn't, then find out why before you pull harder. I watched a wrecker rip the rear axle out of a minivan one day because he didn't realize that it was hooked over a stump....