TryintoModel.
Generally with armor I like to build up the major subassemblies, lower hull, upper hull, turret. I attach any parts that will be sprayed with the camouflage, leaving off tools and other tidbits that will have their own color. I also wait to attach the roadwheels until after all the painting is done.
I like to lay out the roadwheels on strips of masking tape (sticky side up) and strap the strip down onto paper or cardboard. That makes it really easy to spray the basecoat, and even camo patterns if necessary without have to fiddle with a ton of toothpicks or whatever to hold them all while painting. When it comes time to paint the rubber, I will stick the wheels onto the end of a paintbrush, using it as a holder. I dip my brush into a mixture of black and gray paint (the gray gives a slightly "faded" look to the rubber) hold the brush up against the edge of the rim and slowly spin the brush handle. I've found that for me, it helps me have a nice smooth and straight edge, minimizing the chance of accidentally getting black on the rim.
Once all the camo and rims are painted, I'll attach them to the lower hull, attach the upper hull and then move forward on attaching all the rest of the little tools and tidbits (all ready painted of course), attach the decals, then seal everything up with a coat of Future.
At this point come the oil washes, paint chipping etc. I like to do a light dust coat all over the tank to help blend everything together and add to the weathering, with particular attention paid to the upper surfaces that would have had the most exposure to the harsh effects of the sun, as well as the lower hull which will have a lot of dust and dirt. I tend to paint and weather the tracks separately, but may have them on the tank when I spray the dust coat.
I finally seal everything up with a flat coat of 4 parts Future mixed with 1 part Tamiya Flat Base. Attach the tracks if I haven't already, attach the turret and commanders machine gun (assuming it has one) and put it into the display case.