Don't forget how valuable your business card is! It's a mini brochure. Most are fairly cheap, too, so spread them around. Make sure all your contact info is there--website, email, location, phone, etc. And, make sure it states what you do.
Then, put them in everything you mail out--every order you ship, any direct mail pieces, any letter you write, all the invoices you send, and even in with the bills you mail out. If you have a retail store, put them in the bag with the receipt.
Also, leave them at stores where it's allowed--many groceries, laundries, etc. have bulletin boards you can tack them up on or counters where you can display them for free.
Give satisfied customers several, so they can share them with others.
Always take plenty with you when networking--even if it's just your spouse's company picnic or a PTA meeting at school. Don't be obnoxious & force them on everyone, just give them to people you've chatted with.
And, collect other people's cards, too. A quick follow-up note a couple of days after you meet someone who is a potential client or contact is a great marketing tool, too. Just say "it was a pleasure to meet you, I enjoyed our conversation, keep me in mind if you ever need widgets, etc."