I'm a bit of an expert at this :-) ....
I normally check to see if they are a free member. If they are free or they don't have any pictures, I decline them.
Then I normally look at the pictures. If they don't have a picture of the male half in the public gallery, I usually decline them because I've noticed when men don't have pictures up in public it's usually because the guy is ugly, overweight or lacks confidence. If there isn't a picture of the two of them together as a couple, I get suspicious.
Honestly, I can deal with ugly or overweight, but lack of confidence is a total turn off.
If all of the pictures of the woman are boobs and butts, I normally move on. Ditto if the male half only has pictures in a polo and cargo shorts. I like to see a picture of the couple dressed nicely like they are going to church.
Then I look at the certs and the time they joined. If they have been on for a while and don't have any certs, I get suspicious. If their pictures have timestamps from 2008 because they were taken pre-iPhone, I get suspicious. If their last cert was from 2011 and they say "new to this" I get suspicious.
Then I look at their limits. I am here to get fucked by different and multiple men. If the profile shows watch only or "soft" with no sign of a full swap, the other woman better be prepared for me to trip the shit out of her, because I'm getting off regardless.
Then I read the profile. I'm an educator, so as soon as I see a grammar or spelling mistake, they lose points. Lots of misspellings or bad punctuation will cause me to reject.
I also like to see something about them Maybe they like basketball games or riding motorcycles. Whatever, as long as you have a passion that is something other than sex. If their profile is disrespectful shows racism or homophobia, I walk. My husband isn't bi, but seeing "NO bi MEN EVAR!!!!" is a pretty useful window into how much of an asshole the male half will be.
Some more things:
If the man has multiple different kinds of facial hair, I get suspicious. Ditto for women with different hair colors or styles.
A messy house is a huge turnoff. Ditto bathroom mirror selfies.