Instead of focusing on developing an all new trading strategy, I guess adopting an existing strategy and then fine-tuning it according to your trading habits might save you time and efforts. Plus, always have more than one strategy as back up plans may be needed at unexpected times.
Yes, crypto trading does not require anything all new from you but you need to be doing what experienced traders are suggesting always. It is is all about performing in depth technical analysis which is more than enough for making profits regardless of whatever knowledge we are having about crypto trading and how long you are not into crypto trading.
Usually when we are getting back to crypto trading after some gap, it must be better if we start watching the market fluctuations for some days and then doing paper trading before getting into live action.
besides when you are talking about these various alts, definitely, they have their own market performance. so you only need to focus on your portfolio or to projects that you are interested with. because if you will check all the others, it will be a headache.
so each one of them have different strategies in the market, because they have their own pace in terms of development. also, you need to keep up with their social media updates, because that's where you will get a hint on what may happen to their market. don't trade blind. you need to know what's happening around the project. because you can easily lose your funds if you have no idea what's going on with the coin.