I find myself getting stuck on a lot of weaken/strengthen questions in RC because I just don't know how to approach it. In LR I always tell myself to look for assumptions and overlooked possibilities, and in general think of making the premises less supportive or stronger support for the conclusion, and also staying away from trap answers that independently attack the conclusion or deny premises. However, in RC there's not really clear premises or reasoning so I find it hard to wrap my head around how we're supposed to then strengthen or weaken an author's argument, and whether we should consider ACs that seem to independently go against their position or give an independent reason to strengthen it.
Any suggestions on how to think about these questions?
If both of these tests are time-consuming to apply and we should only use them as "training wheels" and not actually on test day, what strategies should we be using to approach these questions in timed conditions?