From my experience for daily trading I only target 3-5% profit, before you buy coin you need to know the normal price of the coin, that is my main point if want to buy or sell altcoin,
Ya true. Unless you know the basic price of bitcoin, you can't judge. How much, if you brought for particular price. If the price of bitcoin increased means,you should brought at the current price of bitcoin. You keep some margin to brought the bitcoin. For example, if the price of bitcoin is 5700$ means,you should not buy more than 5500$ to avoid the loss.