Having read through some of the other processes here, mine feels pretty basic, but here goes. . .
1.) I started by removing as many mold lines as I could, and then added some basing texture (ProAcryl Fine Basing Texture) and a rock to each base.
2.) I then primed each Mech in black primer (Stynylrez) with my airbrush and added a zenithal highlight using white primer (Stynylrez).
3.) Using my airbrush, each Mech got a coat (or two) of Jade paint (ProAcryl).
4.) I used black paint (ProAcryl) for the accent panels and items like the antennas on the Zeus (which are from a tooth brush).
5.) I used gun metal paint (Army Painter) for all the weapons and Leadbelcher (Citadel) for the heat sinks, jump jets, and joints.
6.) The cockpit was done in Retributor Armor (Citadel) with a Seraphim Sepia shade (Citadel).
7.) Next, I gave it a clear gloss coat (Krylon spray).
8.) Once that dried, I used a panel liner (Tamiya) all over. It was a rough combination of a pin wash and an overall wash. Then I used white spirits to clean the panel liner from where I didn't want it.
9.) Time for another coat of gloss clear.
10.) I then applied the decals to each Mech (a combination of Fighting Piranha, Death Ray Designs, and decals from the Robotech Kickstarter Miniature Game). I used a generous quantity of Micro Sol and Micro Set to help them settle onto each Mech.
11.) They then got another gloss clear coat.
12.) Next, using a small piece of sponge torn from the package from another miniature, I applied some Blackened Brown (MSP) sparingly around the Mechs to simulate rust and battle damage.
13.) I used three technical paints from Citadel for the weapon jeweling: Soulstone Blue for the large lasers and PPCs, Waystone Green for the medium lasers, and Spiritstorm Red for the small lasers. For the auto cannons, Gauss Rifle, and machine guns, I simply made sure the insides were black using some Gravelord Grey Speedpaint 2.0 (Army Painter).
14.) For the base, I painting it Intense Brown (MSP) and washed it with a good coat of Agrax Earthshade (Citadel). I also painted the rocks with a variety of grays (MSP). Once that all dried, I applied some basing materials (Geek Gaming Scenics) using Elmer's glue. The plants that I added were from Gamer's Grass.
15.) The base had the front painted in dark gray (MSP) and black (Maxx Darth from Green Stuff World) on the other sides.
16.) Then another coat of gloss clear and finally a coat of flat clear (Testors).
17.) Once everything was dried, I applied a coat of Future floor polish to the laser lenses and the canopy of each Mech so that they would have a bit of shine to them.
I think that is everything I did and I hope the information is helpful.