Two things I'd note on tactics: a general observation that I took too long to learn and a loadout I like to build companies around.
Distance and Movement
Most games only last 5, maybe 6 turns. The average frame will move about 4 ruler units per turn: about 20-24 per game. A play area is, per the rules, 4-6 rulers wide, thus an average of 40 units across. An average frame will only be able to traverse half of the width of a play area; much less if moving using cover or changing direction (based on priorities/targets).
- You need to know your goals before the game starts (move frame 1 here, move frame 2 there, try to take station A with frame 3...). You will have to adjust after first contact, but having a solid plan early prevents you from making a decision to try to move a frame 20 ruler units in 2 turns.
- You need to be thinking about your movement plans for the 3rd or 4th turn during the first turn.
My favorite single frame loadout

This nets a frame with a double spot, a better move (d8 vs d6) that's free (doesn't count as a system), and is effectively a soldier for 3 turns (1d8/rnd vs 2d6 Direct). As most games only last 5-6 turns, it becomes a slightly gimped hand-to-hand frame after 3 turns. And if you're underbidding for defender, this frame gives you a rather effective and safe 3 system frame.
This old has good info on dice odds if you want to see how this loadout stacks up to a soldier.