The Problem with buying and holding is to hope the project is solid and devs are really active on their part if not then you are in a top situation. I will recommend you research and watch the project attentively, know when to sell and when to buy
Choosing a good time to invest is a way to minimize risk in this market as the crypto market is generally a difficult place to predict. I think it is imperative to spend some time researching the coin and considering it carefully before making a purchase because every decision you make will affect your current profit. The situation is getting better now and this is a good time to make money.