Prom dresses -- with 4 DGS I don't think I will be called upon. DD told me I may need to make some boy's dress pants and I told her she needs to keep her good job since even when I made tons of clothes for the family I drew the line at dress pants.
I have made over 100 receiving blankets out of a variety of flannels. I wash it first, then assemble. Only a couple of the blankets pilled. I must be lucky because many of the flannels were from JA's -- some from LQS. I do carefully check the quality of the fabrics -- I make sure it has a good hand, drapes well and has a firm weave. These are washed weekly. I guess I am lucky I have been able to pick some decent flannel.