I always wash and use unscented detergent because that's what I always use.

I wash all my quilts before giving them. I use washable markers most times. I use coldwater Tide period.

I wash new quilts with my regular detergent(Era), a color catcher or two and I don't use fabric softener. if there's going to be an issue with the quilt I want to catch it, not have something happen when the recipient washes it.

Cari

I wash quilts, fragrance free to ensure that all seams, etc. hold well. I use color catchers if I have any doubt that some of my fabrics were not prewashed. It is especially important, I think, on baby quilts. Besides the no fragrance, I always give a second rinse to be sure there is no residue of anything, especially in consideration of a newborn's sensitivity and I make sure the new mom knows that. Besides, the washing blends all the stitching, etc. into a cohesive item. So nice. Just fresh.

I always wash the quilt and I tell the new owner it has already been washed once. If I don’t, the owner is likely to never wash it in fear that they’re not supposed to wash it! I wash it just like the new owner will, in warm water with detergent and fabric softener. It also ensures that the colors don’t bleed and the stitching holds up. I was surprised at how many people were scared to wash their new quilts!

I launder my quilts as soon as they are finished, largest load setting, fragrance free detergent, no fabric softener, and a double rinse.
Regular setting on the dryer. Fragrance free dryer sheets.

I always wash new quilts to get out markers and glue (I like to use Elmer's School glue to sandwich). I use a free and clear detergent and dry the quilt flat on a plastic drop cloth that I spread on the floor or sometimes on the bed. Them, as stated by another person above, the recipient knows the quilt can be washed. I usually tell them about the drying method.

I wash fabric (and batting, if washable) before cutting it.

I also wash the finished item in a detergent as "inoffensive" as possible, and dry it without dryer sheets.

Especially if the item is going to someone that is not well.

I wash mine and tell the recipient: prewashed to remove loose threads and excess dies and to check for loose seams.
I make my own detergent with soap flakes, borax and washing soda. I use the very cheap, little smell dryer sheets.

I hope you don't mind as this is not exactly a comment on your question....just an aside.
I sell quilts and I find that most people that buy quilts are not quilters. They don't like the crinkly look of washed quilts because it doesn't have a 'just bought' look. Hasanyone else experienced that ?