Long term=I don't venture out top 100 normally (unless a super promising project with rep) Ex ETH or BTC right now.
Short term=Anything that has value and that upcoming roadmap something is happening. Ex ETC right now.
Short is dont to short and long is dont too long, that is the way i do it.
I never do very short trading like 1 day or 2 days and i never did trading more than 6 months. This way i do because i think this is smarter when we can make round trade and gain more money but not very short because its very risky
If I have a different perspective, I think when I can get a profit margin then I will sell the coins I have. It's called a trading action in a fast way, I do not think to be able to get bigger profits because I could lose a good momentum. That way I make sure the security of my profits, I would prefer a little profit but can be stable and instens at all times rather than just waiting a long time and we do not get a certainty to get big advantage, it could be even the losses we get. Each choice must have a risk, especially when we invest Altcoin which tend to be very easily affected by various news in the world of crypto.