i only make "cuddle-quilts" which are meant to be used and therefore need washing.
i wash and starch all fabrics before i work with them - to get rid of all the chemicals left in from the dying processes. i find that i sneeze and sniff if i try to work with "new" fabrics - and with the prewashed i have no problems - also any dye remains are washed out and the starch makes them teasier to iron, easier to measure and cut.
once the quilt is finished, it is washed at least once at the hottest setting suitable for fabrics and batting (together with a bunch of color catchers.
as i rarely use the dryer my quilts hang dry - generally over 2-4 lines to spread the weight around.
this ensures that most of the starch. this ensures that all the glue (i like to gluebaste), any remaining chemicals, any germs accumulated during the cutting/sewing/quilting (sneezes, sweat, sometimes blood from a pin or needleprick, dust, whatever), fuzzes and whatever else might have accumulated is removed.
if time allows and i had used lots of starch for a particular fabric.
every quilt gets a small label with washing instructions sewn into a corner of the binding - i print these on printable fabric - generally a full page and i just cut out one when needed...
i make them for 30°C (sensitive fabrics and/or wool batting), 40°C and 60°C (for all-cotton quilts / kids quilts / baby quilts), here's an example of my label which gets folded so that one side shows the logo and the back shows the washing instructions. these labels end up about 1 1/4 inch wide.
i also machine-sew my name and the date into the binding - and sometimes include a label or write something into the quilt. for donation quilts, i also started adding a "pouch-type" label where pieces of each fabric are sewn into the label pouch so that the fabric will be available and similarly used if repairs are necessary.
for my family's quilts, I generally put a ziplock baggie with the fabric scraps aside - this has come in handy especially when my niece's dog decided to let out her boredom or jealousy attacks on Helena's quilt (members of my family don't attempt to make their own repairs - they just send me an email and ask for a visit with my repair kit - so far it works
oooops - long response - but maybe helpful
) lotti