First of all, always max both ur cards before evolving them, that way you get more soldiers, attack, and defense. But you don't have to max level an HUR before awakening it.

Also, do the aw events and kill the featured FAW as most faws have really good skills.

For LAWs, GUR unleashers, multihitters, and atk buffers are the best option.

For LAWs:

Multihitters: summons, random drops from towers, featured tower cards(this event, for example).

Buffers: The best ones can be obtained via summons or random drops from towers. Buffers are sometimes featured as archwitches(minister vielle, for example. She has also returned to the abb ring exchange lineup once) and abb rewards(chase, dark luca).

Team unleashers: Most people use LR unleashers(bright amaterasu: ranking/lr chance summon, azurite: featured tower card), but none are available at the moment. An example of good GUR team unleasher is party crasher(obtainable via summons/random tower drops).

Nullers: featured archwitch(lilith, for example), summons, random drops from towers.

Turnskippers are good for towers, they can be obtained via events, returning archwitches during towers, random tower drops, and summons.