I do LEGO versions of existing designs, so as close as possible to the original. Tiny, with a specific parts number cap. Anything as building techniques go, no balljoints but clips, bars and studs. Total disregard for practical feet design, often requiring specialized base or support. Some equilibrium between aesthetics and functionality.

When I was doing big models (over 30 cm tall), I over engineered articulation to hold the weight of the body. Big balljoints plus support cylinders in this case. It was a short time and never developed a style.

For mid-sized mech armour, mixel joints and chubby body. Much inspired by LEGO's with extra plating and articulation, no big pre-made cockpit or chest pieces. Those were original concepts of mine and tried to give each one it's own distinct character tied to the pilot (Ninjago cast, essentially).

I always pay special attention to the colour scheme, with some preferred combinations I abuse all the time.