Make a list of your hobbies, skills and available time frames. Then make a list of things or services you want or need. Now make a list of who might have the ability to give you what you need. Compare the values you place on these things so you can barter in terms of "this for that". Then contact your family, friends and business acquaintances and make the offers.
Here is an incomplete list of services or products that could be available from you or others: painting, wallpapering, baby-sitting, car repair, lawn care, artwork, resume writing, vegetables, flower arrangements, catering, party planning, discounts, advertisement, tutoring, piano lessons, running errands, roofing...shwew! the list is virtually endless.
I have used a bartering system myself by wallpapering a banquet hall in exchange for a summer of golf and pizzas. The time I used was time otherwise spent sitting in front of the television wishing I could make extra cash for those things.
Businesses
The scale of bartering mentioned so far, is small when you think of business execs or government officials exchanging favors.
Business to business trades are commonplace; for example, tool repair could be traded for hotel rooms or advertisement could be traded between different media venues on opposite coasts.
You recently started a catering business but your advertising budget only allows for word of mouth. No problem, offer a catered lunch to radio executives in exchange for airtime and make their catered affair spectacular--kudos for your service from the execs may even be included in your ad.
A printing company might trade printed flyers for your new cleaning business in exchange for their offices being cleaned.