Dollieh Sanctuary

The seller mybayer2008 on eBay has some really nice doll clothes, stands, wigs, elastic etc. I've ordered from them a couple times. They can also custom make doll clothes to specific colors or measurements. Link:
http://www.ebay.com/usr/mybayer2008?_trksid=p2047675.l2559

Doll Peddlar sells a ton of stuff from Pullip, to ABJD, to Tonner and more. DP sells dolls, as well as doll accessories. They also have an app on iTunes. Link:
http://www.dollpeddlar.com

SugarLattice makes adorable outfits for Pullips, 1/6 Volks, Blythe, Azone, and Obitsus. I think they also have YOSD stuff. SL makes adorable wigs for Pullip, Blythe, and 1/3 bjd, as well. SugarLattice also sells some adorable Pullips-- pre-owned, new, and custom. Link:
http://sugarlattice.storenvy.com

Dollheart also makes gorgeous outfits for BJD. I own the Bella Dark one--it's incredibly well made, lined, and looks fantastic. Link:
http://www.dollheart.com

Here a place for doll stockings.

http://thedaughterwhosews.com/

For BJD:

Think Pink, Nijmegen, the Netherlands. Ship world wide. Good shop, also make custom wigs. I bought 10 dolls and their accessoires/clothes is 3 years from them.

https://www.think-pink.eu/nl/

Requiem Art Designs
This is an Etsy shop full of downloadable doll clothing patterns, in many different sizes! All her patterns are easy to print at home PDFs. I've worked with her Monster High/Ever After High patterns and they're really great! She includes nice, clear instructions for each pattern too. She also does patterns for Barbie, tinies, 1/4 scale and 1/3 scale dolls!

I don't know if it's been posted here yet, but this website has a section of stuff that can fit various sizes of dolls.

https://www.miniaturesweethk.com/

Just go to the dollhouse section and scroll through. Things aren't listed by scale, but the individual listings so have the size of the items listed in millimeters. There are some really cute plates, bowls, and cups that will work great on a 1/6 scale.

I just found this site.

https://meandhouse.aliexpress.com/store/3719010

https://bid.alderferauction.com/ui/auctions/91747