To be honest if you do things for people they'll do things for you. The basics are experience counts alot, always keep on top of new technology,
SEO is not a code google tell you want they want, stick to the rules, exchanging links are helpful if the links are relevant, if you want to be the best put in the work there are no short cuts and the most important thing.....be nice you never know when you might need a favour.
Your reputation is all you have to live on in this business, the internet brings people together faster and bigger than any other technology, which also means if you make enemies more people will know about your faults faster and bigger than anything before.