Keep air vents and filter for exhaust fans (and heating and cooling systems) clean. This is all part of general ventilation system maintenance, but if your craft involves the creation of dust, you may have to clean or replace these filters more often. If you have some design leeway in your crafting area, install an exhaust fan if there isn't one. They can be installed in any room, not just a kitchen or bathroom.
It's a good idea to have at least one place in the house where the kids don't have to worry about making a mess. This is where they (and you) can do crafts.
If your basement or attic is full of old junk, consider making it something more enriching to your family. If space is really at a premium, think about converting part of the garage. A spare bedroom that only gets used by guests once in a while is probably better used by your family. (You can always turn it into a guest room if you need to.)
Wherever you choose, make sure your crafting area has these essentials:
Adequate lighting. It's easier to avoid accidents when you can see what you're doing!
Adequate ventilation. Pick a place with windows and, ideally, an exhaust fan. To increase ventilation, you can add a window fan to either bring fresh air in or suck old air out, depending on which way the fan is pointed. Cross-ventilating with two windows is a great idea.
Fire safety. Wherever you decide to do your crafting, make sure you have a smoke alarm and a fire extinguisher nearby. For more on safety tips while crafting, see Rules for Safe Crafting.
Nearby storage space. If you have a clearly defined, easy-to-reach space to store your crafting materials, you'll be much more likely to put them back when you're done with them. For more on organizing your crafts, see How to Store your Materials.
A water source. A regular sink will work, although a utility sink (a large, deep sink; also called a slop sink) is ideal if you'll be using dyes, pigments, or anything else that will stain. If you're planning on using a garage or basement area, see if you can install a sink.
Garbage disposal. Have an adequate trash can or cans near your crafting area. Plastic cans are usually best, since they are lightweight, can't break, and are easy to clean. Use the trash can often and clean up as you go along.
Room to spread out. Having enough room to work also helps avoid messes. How many times have you knocked something over because you were working in too close a space? If you can, pick a space that isn't in the middle of everything. If that's not possible, choose an area that's not in use every day; for example, part of the family room or den.
With your work area carefully chosen, we can move to the process of outfitting it for the easiest cleanup possible.
Your Crafting Table
For convenient crafting tables, invest in a couple of six-or eight-foot folding banquet/conference tables. (I bought mine at the wholesale club.) They're extra-sturdy and you'll find a zillion other uses for them.
Not only do you want efficient space to work, but while you're at it, why not make your work surface easy to clean?
If your work table is wood, which is porous and prone to scratching, think about covering it with some kind of plastic laminate (the shiny or almost-shiny kinds are easiest to clean) or several coats of polyurethane.
Consider putting a piece of glass over a non-scratch- or soil-resistant surface to create an easy-to-clean surface for crafting.
Remember, if you pick the kitchen table as your crafting area, you know you'll have to pick up and clean everything before the next meal.
Four Walls and a Floor
Once you've chosen a place for your crafting table, make sure the surfaces around it are easy to clean:
Note how close your work surface is to the wall. If necessary, consider covering the wall with vinyl wall covering or laminate.
Get rid of the carpet and put down some vinyl flooring if you can.
A waxed floor is easier to keep clean and safer. Wax provides a protective shield and gives a smooth, even surface to sweep or mop. So if you're working on vinyl or linoleum flooring, wax it before you craft next time. If you're crafting in the garage, go to the extra trouble of sealing the floor with a commercial concrete sealer. Sealing concrete makes it much easier to keep clean.
Avoid tracking stuff from the crafts area into the rest of the house by putting mats down on the floor in the doorway of the area. Make sure they're good-sized mats (the Astro turf-type mats seem to work the best) and shake and clean them often. Preventing dirt is one of the easiest ways of cleaning without cleaning!
Analyze the work surfaces and adjacent areas in your crafting area for cleanability and you'll undoubtedly find still more ways to make your crafting life easier.