i prefer a little guidance... when i respond to a swap partner i may say make it scrappy or this is what my decor is, so i try to leave it (wide-open) as far as what to do but offer some idea of where it will be used so i'm not as likely to receive things that i open and say...
now what the heck am i gonna do with this? it clashes with every room in my house. in the past 5 years this has only happened once...the one time i said...oh, it doesn't matter, make whatever you want,i will love it, what ever it is....well, turned out to not be so true (and it was even from someone who had been to my house) since then i always offer at least a little (likes/dislikes guidelines)
when i get a swap partner who has offered no ideas i usually try to go to them directly and ask a couple questions...like, getting ready to work on your table runner, do you have a favorite color? or is there a favorite block you just love and wish you had something with? do you like modern fabrics? florals? ...
i ask questions...if all i get in return is...do what ever you want i still can't leave it quite alone...i go to their profile and try to find out a little more about the person....has the person posted some of their work? what seems to be their (style)...do they have kids? there are (clues) that i look for. if i really can not get any info i finally make what i want and hope.