The English letters depend on the original purpose of what you want to draw. For example, if your piece of clothing commemorates the Olympic Games, then it should be written with the letters "Olympic" or "Beijing" on it. If it’s for entertainment, then just write HAPPY simply, or ANGEI cutely... it’s all fine

It’s not necessarily the case with lines. It depends on the English style you write, and compare it with the style. Design it yourself, it’s OK if you think it looks good

Purely my personal opinion