Avoid Bad Hair Days
How To Avoid A Hair Crisis
Very subtle seasonal changes are much modern and flattering than than total redesigns. If you are just bored, before you go for a drastic hair cut, try changing your styling first. For example, if you always wear your hair straight, try styling it curly; if it's always curly, then put some product in it and blow-dry it glossy and straight.
Good condition is also critical. It doesn't matter if your hair is long or short, if it's in bad condition it will look like bad hair. So before coloring, consider if the condition is good enough for color - you don't want your hair to look even worse.