This is a nice guide @dredo15 Leasing SP will sure give you a lot of influence and with this you can change Steemit community for the better. Even an upvote with "only" 14 cents sometimes makes a difference for the author and gives him the motivation to continue things SP can do.
Most of the time the worth of your up vote determines how much you can shape the attention of a post. For instance giving a post an upvote of 20$ will easily send the post from new category to hot and thus increases the exposure for other Steemians.