The best way to earn money in short time with a target of 4%-10% of your investment is to closely research the market, choose a coin which is moving up and down, find the trend and buy in low and sell in high using your own target.
Also note that do not put your all investments. Do not invest more than 30% of your investment. if price decreases do purchase more at lower price to make it average. Do this based on proper research. Once you can make a good average price, once the price increases sell at your target.
This is my suggestion for new investors. Expert people know what to do. Best to start with crypto is Spot Trading. Gradually learn other features and most important is to learn the market.