How do I design a screen which works for cross mobile devices

nowadays there are too many devices with different height and different aspect ratio, should I make the design for a smaller device and top of that I add a percentage respectively? or there is any other way to look at?

Start with the smallest device you’ll support and then, yes, use percentages or rems for your sizing. You don’t have to do screens in all the sizes. Usually, the smallest and largest using proportional sizing is enough.