This is a very complicated topic, but I'll give it a go:
One thing we all need to remember is that we have been given the mind of Christ. If we are delighting in Him and focused on Him more so than we are focused on worldly things, we will grow in the ability to hear Him. He is always speaking to us, but most of the time we are so tuned-out, we don't know how to hear Him.
Spntaneity is not a bad thing, esp. if we are focused more on Him. If we are not seeking first His kingdom and His righteousness, this spontaneity can get us into trouble.
Also, about your strengths, I beieve God has given you those and you can trust them to a point. But the real test comes when God calls you to do something that is not included in your list of strengths. He sometimes calls us to do something we know we suck at, so that He can get all the glory when He works it out perfectly thru us.
He will test us in this way. Not so that He can know how we're doing, but so that we'll know how we're doing.
To answer your question, though; the area I'm most tempted to rely on myself is probalby on my rediculously good looks. It's like a burden sometimes, but it is what it is. You know that saying, 'beauty is only skin deep' well that something only ugly people say.
