If I have 1BTC So how did I use to invest in different Coins
If I had 1BTC I would definitely sell when the market rises and buy bitcoins again when the market falls. I will invest in coins like Ethereum with the profit I get during this period but after Bitcoin I will not prepare myself to invest in any currency other than Ethereum. I will always force myself to go with low risk coins I will never force myself to invest in high risk coins. Because I don't like to take too much risk I always prefer to proceed with less risk.
If you sell bitcoin when it goes up and buy it back when it goes down, that's not essentially called investing, it's a commercial way to make a profit. That is an option but I think it would be less optimal than continuing to hold bitcoin. Bitcoin has the power to grow in value over time. Just holding or you can hold 0.6 btc, 0.4 btc for diversification would be more suitable than selling all bitcoin just to buy eth and a few coins with REKt potential.