Here's the example of how I invest/trade: I've done a lot of research on 2 coins: ETH and NEU (Neufund). Both have solid use. My team uses Ethereum for software development so I follow closely it's network usage, and I know pretty well how many companies use it for various purposes. Neufund is the first Equity Token platform, it's economics are clear to grow and generate income, I follow it's channels closely and know what's happening. Besides these I also own Bitcoin for diversification and cashing out. Besides these that I know well and follow closely I do not buy any other coins, I only earn tokens of my clients through work. When any of my holdings get to gains of over 50% I start selling them slowly, to USDT or to other tokens if they did not grow as fast. For example I sold ETH for BTC when it reached 0.1. Then if the coins drop over 60% of the peak, I start buying them. I never sell on the downturn or buy after token is over 80% of it's historical high.
This indeed is a good strategy. My strategy are similar while buying with fiat.
I select a number of coins which I believe do have a future. I buy when they are going low or high and are below 50% of their peak value, I keep on buying the coin if it keeps decreasing in a decreasing amount while stops buying when it keeps increasing and I set 50% of the coins on sell order above x2 of my buying price hence bringing back my investment in any time in future.
It looks like we almost have the same strategy, the only difference is that I have more coins that I can diversify like Monero, NEO , Bitcoin, Ethereum and NEM. Other tokens that I own are came from campaigns.