Ways I've seen it done by others:

- Body language.
- Acting out and not hiding it (obvious self harm).
- Behaving in a manner that attracts attention for example- walking in the middle of roads where you know cars are too slow to hit but someone will have to pay attention, getting in trouble with the law etc.
- Talking around the subject and setting the situation up so that people will then ask and find out more.

The way I try to do it is find a way to just override the fear, the fear cannot kill me and won't go away till I address the problem so there is no point in holding information from people. If I want help I need to ask for it.