You will need two or three large "banquet" size tables placed together. This works well for layering and basting a quilt and is easier on your back. Check out a church, library, or community room and ask if you can use their tables to baste your quilt. It might be a good idea to have a friend who will help especially if you have a very large quilt. You could work together and pin baste two quilts in an afternoon.
One of our local groups meets in a church hall with banquet tables. The standard height of the tables are low and cause back strain so we cut 16" lengths of 2" diameter PVC plumbing pipe and placed one of them under each table leg to raise the table so we don't have to bend and strain our backs. The length you cut your PVC pipe is determined by how long the table legs are in comparison to the height you would like to have the tables. You may want to cut them a little longer and shorten them as necessary.
I suggest using something closer to home: a bed made higher with either raisers like pvc pipes or storage tubs placed between the mattress and the box spring - perfect height!
Place the backing fabric on the table with the wrong side of the fabric up. Tape the edges of the backing to the edge of the table using masking tape, or use basting clamps (see note below), or 2" binder clips available at office supply stores. The basting clamps easily slip over the edge of the fabric at the edge of the table holding the fabric taught. The binder clips are hard to open and clamp if you have arthritis or weakness in your hands. Your backing needs to be firm or taut but not stretched. It is important for your backing to be taut because if it is not taut you will have puckers when you quilt.
Instead of using the 2" binder clips, we use the metal clips (not the plastic ones) to hold picnic tablecloths on the table, that way there is no problem with people who have arthritis. The clips fit nice over the edge of a table that is about two inches thick.
The next layer is the batting. Take the batting out of the package and unroll it or unfold it and let it rest at least overnight. Or you may fluff it in the clothes dryer for a few minutes to take out the wrinkles. Read the package directions for fluffing in the dryer or for pre-shrinking instructions. Some cotton battings will shrink after the first washing. If you want the antique crinkled look of your quilt don't pre-shrink cotton and cotton blend battings. If you do not want the batting to shrink, pre-shrink your batting as recommended by the batting manufacturer and use the instructions printed on the batting package. Different brands of batting have different methods for pre-shrinking. Do not pre-shrink polyester batting; only fluff it in the dryer.
Layer the batting on top of the backing by spreading it carefully and not stretching it. You will want to sort of "pat" it out on the backing to get it flat and smooth. If the batting is stretched slightly, it will relax when the quilt is taken off the basting table and cause puckers when quilting.
Then layer the quilt top -- right side up. Smooth the quilt top carefully so you don't stretch the batting under it. Place long quilt straight pins about six to eight inches apart along the outside edge of the quilt top through all three layers.
Baste the quilt with safety pins. You will need several hundred for a large quilt. Be sure to buy good quality safety pins that are rustproof. Inexpensive pins that rust on your quilt are not a bargain. There are some safety pins available that are "bent" especially for quilt basting and they are easier to use...
With safety pins, start pinning in the middle of the quilt. Place the safety pins approximately four to six inches apart depending on the type of batting you are using. Polyester batting is slippery and would need the pins to be closer whereas cotton batting clings to the cotton fabric so six inches apart would be plenty. As you pin from the center, smooth the quilt top toward the outer edge and continue pinning. When you get to the edge of the quilt, remove the straight pins and replace them with safety pins. I don't close the safety pins until the entire quilt is pinned. Then I go back and close all the pins. That way if you need to move pins to smooth out an area they are easier to move.
When closing the pins, your fingers might get sore and tired. I use the serrated edge of a grapefruit spoon to help me close the pins. Just place the serrated part of the spoon under the point of the pin to bring it toward the pin latch to close. The grapefruit spoon does help you from getting sore fingers.
When you have pinned the entire quilt, remove tape and clips from table and you are ready to quilt. Begin by quilting in the center of the quilt and quilt toward the outside edge. As you are quilting a specific area you may remove pins as needed to facilitate quilting.
A note about thread basting -- I have had some of my larger quilts machine basted by a long arm professional quilter and it worked well. She loaded the quilts on her frame the same if she were going to quilt them but only thread basted with large stitches in one direction.
If you thread baste either by a long arm quilter or by hand be sure to use basting thread as it is weaker than your quilting thread and will break first. You don't want your quilting thread to break when you are pulling out the basting thread. You want the basting thread to break. When thread basting by hand you would need to baste a grid of lines in both directions about three inches apart. Some quilters recommend water soluble thread for basting. This would work well because the water soluble basting thread could be removed with a spritz of water.
Safety pin basting is recommended over thread basting because the safety pins hold better than thread basting and can be removed easily as each area of quilting is finished.
NOTE: Your local quilt shop can order "Clamps for Basting" by Me Sew from Checker Distributors or use an online search engine and type in "Basting Clamps" or "Clamps for Basting" and you will find several online stores.