I usually follow a few steps when I make squads. This is just meant for basic design, obviously when designed and picking a squad for higher competition there is alot more thought that is much more difficult to just put into steps.

1. I feel a squad needs atleast 60% of the points put into pieces that can actually deal damage and win the game for you. If the squad needs more than 40% of the points in activations and commander effects to work...then I generally throw out the squad idea. Some combo can be so powerful they break the rule, but most of the time thats a decent ratio.

2. Whats my plan for getting to gambit first round on my map? Whether it's palpy on throne, r2 AD tow, thrawn/panaka swap, yobuck/landspeeder extra movement etc, I just like to have a plan for it.

3. Activation check. 100 points needs 5-7, 150 needs 9-13 and 200 needs 11-14. If I put together a squad and then look at the activation count and my 200 point squad only has 9 activations, I rework the design. This is also just some basic numbers, there can always be exceptions which is affected alot by the amount pieces your opponents tend to play.

4. Door control check. If I couln't fit in an override piece, I like to have atleast 4 uggies. With override, I still want 2 uggies minimum (in 100 pts this is not always the case)

Go to the forum named Tactics under general,
they could get good suggestions there.