fecals ? (how fresh)

the hotter the better, even if you have to take it later just catch a fresh one put in a ziplock almost all the way sealed but where some air can get in (you dont want that hot steamy wet turd to start growing mold or fungus in a nonventalated bag) and bring it to em as soon as you can even if it is the next morning.... leave it at normal room temps... do not freeze or refridgerate that could compromise the female more so than leaving it at room temp. if its a little dry they can still do a fecal just fresher samples give you the most accurate results

I guess this only comes with experience, but how do you know what is a normal looking fecal and which is not.
I just got a microscope and I am trying to figure this out. Some of my gecko's have got worms (busy treating them). I took a sample from the ones with worms and the ones without. I could not see a distinct difference.
Ordered a book on reptile parasites, maybe that will help. Is there any websites that could help in the mean time?

thanks

paul