I have never done it before but have always wanted to. I would love to come and help you! Or at least help from this distance.
I have tested patterns for folks, usually they send you the pattern, you make the item noting any changes you think might help, and take pics of the project. Send the pics and the pattern back to the designer, and when the pattern is finished, the designer will send you a copy of the completed pattern.No more testing for me, lol - I need to start getting my own patterns going! Too many ideas and not enough time!
I've done pattern testing. Like Allie says, the designer sends the pattern and instructions. I switch off my brain and follow the instructions very literally, pretending I have no sewing experience. I write detailed notes about everything from the seam allowances to the spelling and sent them back to the designer.Because of the work involved in pattern testing - not just the sewing, but the notemaking, and the occasional annoyance at the instructions not yet being perfect - I only pattern test something I actually want to make. I wouldn't do it for a random pattern that I wouldn't otherwise be interested in.
I have never done it, but have thought it would be interesting to try. No one has asked me yet though...do they send fabric with it?
I've done it before and would love to do it again! When I did it, the designer sent me the pattern, then I made it, checking to see if the directions were clear, etc, and the pattern worked out right and made sense. I gave her my input when finished, so she could compile everyone's advise to improve her pattern and directions.