Any tips on how to stop thumbsucking?

My son has been sucking his thumb since he was about one month old and now he is almost seven months old and sucks his thumb alot. He never took to pacifiers. I am concerned because now he has started getting teeth and I want them to be straight. I am more worried because I was a thumbsucker for most of my childhood. If anyone has any tips for me I would greatly appreciate it so I can have him stop before he continues and becomes more dependent on it.

Thanks Mela