Seriously, try Elance instead. My top tips are:
Keep your prices where you want them
Write serious, thoughtful, relevant and detailed bids that demonstrate your professionalism
Have work samples on your profile and attached to each bid that showcase your expertise
I've won plenty of work where my bid was the highest, and I've also been told that the client wants to hire me, but could I reduce my rates, and I said no.
When you get to see other peoples' bids, it's worrying how many are a generic cut and paste, or say, "We have all the expertise you need for your project and we give you best price"
Some clients will always be bargain hunters and will under-value you if you let them. You can spot them with phrases like, "This should be a simple job for someone who knows what they're doing" or "I'd do this myself but I don't have the time".
They're like people who take their car into the garage and say, "I've taken the engine out and stripped down the cylinders, and all I need you to do now is change the broken bit and put it back together, it shouldn't take you long, I'll give you £5 for it"
Moon on a stick... haven't heard that in years. Made me smile.
Sell your services on quality and price them to reflect that.
Of course, if you're not very good then you're stuck, really. Or if your service is web design or SEO. That's an incredibly commoditised market, and very difficult to maintain prices in, unless you're offering some kind of packaged or managed service, and then you're quite right, people tend to go to agencies for that rather than Elance.
What is your service?