Hardest thing I ever did was write a simple pattern for crib quilt for LQS! I like finished sizes(quilt & blocks); measurements that aren't 8th's; pressing instructions; easy way to enlarge; both a picture of the finished project and also schematics (especially for things like bags, which I struggle with)

I want a clear picture and concise instructions. I like to see block measurements, pressing instructions, rulers or templates needed and yardage. I like the “shopping list” on the back of the pattern and the picture on the front so I don’t have to remove it from the clear plastic sleeve. I also use patterns in books and magazines and I want clear instructions.

i agree. just as not every teacher can teach, not every pattern writer can write patterns.
and from my own experience with finding pattern testers, it's very very difficult to find someone to test pattern & give feedback.

it takes time to develope pattern idea, write & illustrate, produce sample ..so i do understand people's slow response to helping with testing. tho professional pattern writers probably have a "crew" of people to test & help.

ditto! to all you say.

Well written instructions that are checked for both spelling and grammar.
Instructions should be concise, not overly wordy.
Photo of the actual completed quilt.
"Generous" fabric requirements - not just enough to make quilt.
If special tools/rulers required noted on front page as well as inside.
Size of blocks and size of the completed quilt.
Designer contact information for questions or problems with pattern.