When I worked in the City, people (agents) would often call me to see if I was interested in a new job. I got into the habit of asking them to sent a spec (specification) over to my email address. Why? The spec itself might go on to be important or it might not, but relly, in the first instance, I just wanted to satisfy myself that a spec existed. A spec showed that the clients had, at least, put some thought into what they wanted. Furthermore, clients often need to produce a spec internally to receive budget, so a spec helped to know that they weren't just on a fishing expedition. I'd sometimes get some bright spark of an agent saying, "this role is so new that there isn't a spec yet", to which I'd just say, "well, when there is one, send it over".
Another thing with the type of work I used to do, was duration. If a client had a permanent need for somebody in my role, but only wanted to offer a short-term contract, a probation period, if you like, then fair enough. I was quite happy usually to take my chances that I'd do enough during that initial period to impress. Alarm bells started ringing, though, if a client said they wanted a designer for just a couple of months, since a decent project could be around the 10-man-year length, or maybe 18 months duration, and you really need a decent amount of time to get your teeth into something.
So I ended up looking more for things that should be avoided, rather than things with potential. The things with potential were the ones left over after I'd rejected the things which fell at one of the hurdles. It is the same, really, now, although there are altogether fewer vacancies locally so the scale is smaller. Indeed I haven't seen anything in almost a year which ticks all the boxes. I saw a funny one yesterday. Somebody was offering just a three-month contract for a Head of IT. Obviously interim - someone must've been taking a leave of absence and the company didn't feel they could manage. But who do they seriously think will take that on? What do they think somebody can achieve in just three months? I must admit that I could happily take on a "head" role these days, but reall, I'd want to have a bit of time to see the effects of any changes I introduced.