Ultimate basic is to buy low sell high. Nothing else matters as much really imo. After you profit, it's just a matter of how greedy you are for profits before you're able to determine when to pull out or continue risking it. Personally from my experience if I'm doing shorts, a profit of 3-4% is usually enough for me to pull out, and if I'm greedy then a maximum of 5. The best I had while waiting in a day was 10%. I'd suggest looking into coins that are booming or are moving in an extremely volatile way. If you time it right you can profit pretty good in a couple of hours.

For long term, as you've said, I just DCA and wait a couple of years. It's just a waiting game after all.