I don't think you should trust just anyone, but allow yourself to trust the people your heart tells you that you should. That's a essential part of love, friendship and relationship.

If you are deciding about wheter or not to trust an individual person, look at their "track record" in your life. Have they ever given you a reason not to trust them? If so, what was it and why? Did you confront them about it? How did they handle your concern? Are they trustworthy in general? I have done this with several people I was "waffling" about trusting and most often, I found they had never given me a reason not to trust them and they deserved a chance to earn my trust.

Tell yourself "I trust _____". Reminding yourself why you do, why you can and why it's important. Tell them "I trust you." Let them know that you are counting on them not to break your trust.

Finally, be trustworthy yourself. That's the best way to trust and be trusted.

Like it or not, we all subconsciously have to trust. I trust the chair I am sitting in not to break. I trust that the food I am buying isn't poisened. I trust that the sky isn't going to fall when I step outside. Those may seem like silly examples, and they are. But the point is, we can't survive without trusting somethings and someones. The important thing is to find good people to rely on so you can support each other and make trusting a little easier.