These are a few very simple henna patterns. Just very basic. Henna itself is much more intricate, but that becomes too tedious to ice.
Don't use too many patterns at once, it looks too busy. Select one or two and repeat to create your design.
When henna paste dries on the hand it is a deep dark brown. When it is washed off, the skin gets dyed to a deep orange red, sometimes almost black.
Arabic henna patterns are darker and more bold than these. These are typical of Indian Henna.