Bizarre hygiene habits
Everyone marches (and cleans) to the beat of their own drum, but there's a limit to what we're willing to work with. The moment we find out that you keep your toenail clippings in a jar or eat your scabs, it's over. Regardless of how attractive you may be, there are certain gross habits that you just can't get past. If you found out that Jennifer Lawrence or Benedict Cumberbatch secretly licks their boogers, you'd look at them in a whole new (uninterested) way.
Working is a really good thing. It's way better than being unemployed. But when we're first getting to know each other, maybe it's not the time to rant about how great/terrible/important/meaningless your job is. Not only would we like to think that you have something interesting to say that doesn't revolve around your career, but most people probably aren't looking to get involved with someone whose entire life revolves around their workday. Money and employment are nice, but they aren't everything. If that's all you're concerned about, we probably won't be getting your number.
We're all for treating our significant others like royalty (or as well as we possibly can) and going out of our way to make them happy (within reason), but if it's apparent that someone is going to expect that sort of treatment, then count us out. A relationship is a partnership, and when one person just expects the other to treat them like a god/goddess without reciprocation, then why would we even enter into that mess of a relationship? We're sure there are guys out there who want to be servants and do nothing but provide for an attractive woman, but we're not among them.
By no means are we saying everyone needs to look picture perfect at all times. There are plenty of times for baggy T-shirts and sweatpants, but usually not when you're looking for a first date. Sloppiness isn't just about your clothes though. You don't want to be that hammered drunk guy/gal who can't stand up without leaning (unless the person you're talking to is equally drunk), and a little bit of grooming can go a long way, for everyone. It's awesome when you hit that point in a relationship where you don't really have to try super-hard anymore, but, until you're there, just try to make sure you're presentable anytime you might run into someone you might want to date.