Anything that makes it "click" for you could be called a dream sign. The reason we look for things that happen often in dreams is that we can condition ourselves to react to that sign.

In your second example, you could try to associate help from female companions in general with dreaming. Every time you get such help in real life, try to remember to do a reality check. Even if you are 100% positive you are awake, do a check. Eventually, what happens is that you start to do that check in your dreams, just by force of habit. Remember that what you do in your waking life you often do in your dreams as well. If you automatically do a realitiy check every time a female helps you, gives you "hints" about something, or just accompanies you somewhere, you'll start doing this in your dreams as well. The only difference is that when you do the check in the dream and it fails, you will know you're dreaming... then you're almost there!