Hi Marvo, welcome to the forum. And, yes, you will get a number of varied responses to your question. You may have to experiment to find out what best works for you. Keep in mind that you may use different techniques for different models. Here is what works for me most of the time. I build the hull and turret, put the turrest in place and then paint. That is if there is not a lot of overhang from the rear of the turret. The wheels, gears, sprockets, etc are all sprayed off the vehicle. I want to be sure that the hull behind the wheels receive enough paint and color. Next I add the "tire black" to all the rubber surfaces of the wheels, assy. the wheels and add them to the vehicle. The tracks are next painted and initially weathered to at least some degree. I next add the tracks, tow cables, tools, antenae, etc. and weathering. Decals are added at some point prior to weathering the whole vehicle. I usually play this by ear. Like I said, find out what works for you. But by all means have fun! Good luck on your models.
Ed