Antique quilts are very fragile and should be cleaned very carefully. If the quilt is very fragile you might want to just enjoy it in its aged condition. Displaying a very loved and used quilt just as it is would be appropriate.
If the quilt is damaged in any way, repairs should be made before attempting to clean the quilt.
The following recommendations are only recommendations! Each individual should make her own decision as to how she wishes to clean her quilt. There are so many variables involved that need to be taken into consideration it would be almost impossible for anyone to evaluate how to clean a quilt without seeing the actual quilt.
There are several ways to clean an antique quilt. If the quilt has a slight odor wait for a warm sunny day and simply lay it outside on a clean bed sheet. Cover with another clean bed sheet and let it air out. Turn the quilt over for part of the day. Be sure to take the quilt inside before evening dew so it doesn't get damp.
If an antique quilt is simply dusty you can vacuum it with your vacuum cleaner. Put the upholstery nozzle on your vacuum cleaner. Tie an old nylon stocking over the nozzle. Vacuum carefully on both sides of the quilt. Another option would be to cover the quilt with very fine textured nylon bridal illusion fabric and vacuum very carefully.
If the quilt is really dirty and fairly sturdy it can be laundered by hand using the following method. Place quilt in a clean bathtub. Fill with lukewarm water. Luke warm water is just slightly warmer than cold -- about body temperature. Place mild soap made especially for washing quilts and dissolve. Let the quilt soak. The time needed to soak a quilt is determined by how dirty it is. Do not agitate the quilt. Do not wring or twist the quilt. When soaking is finished drain water and repeat if necessary. Rinse by draining tub and adding cold water. Do not wring or twist. Repeat rinse as necessary to remove all soap residue. Squeeze water from quilt by simply applying pressure to the quilt. Carefully take quilt out of bathtub supporting all areas of the quilt so the thread doesn't break from its own weight. Dry the quilt outside on a clean bed sheet, covered with another clean bed sheet. Do not hang an antique quilt on the clothesline. It may take more than one day for your quilt to dry so you will want to bring it inside and put it out again the next day.
Do not dry clean your quilt. Dry cleaning solvents could be damaging to your fabrics and batting.
Remember, your antique quilt fibers are very old and could be brittle. Whatever method you use be very careful.
How to press seams
Pressing can be a very confusing. Traditionally -- in hand piecing we have always been told to press toward the darker colored fabric. In machine piecing the direction the seam is pressed is not as critical although most times I still prefer to press toward the darkest fabric. Especially if you are using white, cream, or a print with a very light background, pressing toward the dark would keep the dark seam allowances from showing through.
A good rule to follow especially in strip piecing is to press in the direction stated in the pattern. Most pattern designers carefully plan pressing directions for ease of future assembling so you would want to follow their directions. That way when you are working on the next step you will have your seam allowances pressed in the direction required to continue the piecing process as the designer planned.
When piecing individual blocks and the block has a center area it is usually recommended to press seam allowances toward the outside although this is not an absolute rule. Also if several seams are intersecting from one direction and the other direction has fewer seams, press in the direction of the fewer seams.
At other times you might want to press seam allowances toward the piece you want to "come forward" or stand out. By pressing seam allowances toward these particular pieces they become prominent because the pieces surrounding them tend to recede.
Many quilters press seams open. Especially if piecing an eight point star or another block that has eight, twelve, or sixteen pieces meeting at the center, pressing seams open will definitely help the seams to lay flat. There is controversy about pressing seams open in quilting, but many quilters with experience in sewing garments are perfectly comfortable pressing seams open. Our present day sewing machines and threads make a "lock-stitch" that is much sturdier than our grandmothers had with hand piecing so we should not be afraid to press seams open if necessary to reduce bulk.
The direction you press your seams is also determined by how you will be quilting. If you will be machine quilting "in the ditch" you will want to press seams away from where you want to quilt. This way you are quilting only through the three layers of the quilt "sandwich" rather than the additional layers of the seam allowance.
If you will be "outline" quilting (1/4" from seam) it really doesn't matter the direction of pressing for quilting purposes because you will not be quilting in the area where the seam allowance is.
Look at your block carefully and decide the direction you wish your seam allowances to be pressed rather than following any particular rule. As you become more experienced at piecing, pressing will become easier and you will know the direction to press each seam allowance.