There are two things that I think a title should cover - the subject of the question or discussion (i.e. a particular trick, or tricks) and the aspect about it/them that you're dealing with. Some titles cover neither of these - many cover one and very few cover two.
Titles like "Help", "Question" and "Advice" in the Advice forum offer no additional hint beyond what was already given by the forum title as to what the thread is about. Neither do threads with the title of a trick, posted in that trick's PO forum.
Some titles cover the subject of the question or discussion, like "Stealth Pen" if put in, say, the General Magic forum or Street Magic forum. So there is a hint about the nature of the thread. However, there's no mentioning of what aspect of the Stealth Pen is covered. Is it a question about whether it's any good? Has it broken? Is it to do with problems performing the trick? Is it just opinions of the trick? We'll never know unless we click on it.
Other titles cover the aspect of something but we don't know what the something is; things like: "What should I get?" or "What do you think of...". They may be referring to products I use on a day-to-day basis and can give excellent advice on, or maybe they're about a trick I've never heard of. I'll never know unless I click it.
Informative titles will usually be a summary of the question, such as "Is Professor's Nightmare Particularly Angle Sensitive?" (and the thread just elaborates on it) or they will mention a trick and an aspect of it: "Professors' Nightmare and Angle Sensitivity". If you saw those titles, you'd know what your answer to them would be before even clicking on them. That's the sign of a good title.
There are exemptions to this titling procedure: for example, giving your thread the title of a trick in the Trick Reviews forum is enough to let everyone know that you are giving a review on the trick. Usually it's better to emphasise the fact by putting "review" in the title to differentiate it from someone who's requesting a review. The same goes for in the PO forums. You usualy don't need to mention the trick because it's implied from the forum title.
Probably an issue that is just as important is that of vague questions. "Which is better - Greed or Visi-bill?" isn't detailled enough to guarantee any detailled responses. On the other hand, posting, "I've been into magic for a number of years and have quite a wide knowledgebase, although I'm not the most comfortable when it comes to complicated sleight of hand and angle sensitive tricks. I'm looking into performing tricks that are suitable for performing at a bar (since that's where I spend most of my time). As a magician I often get asked, especially by drunks, if I can make money from nothing, so I thought I'd equip myself with a "making money" trick. I've looked through Penguin magic for tricks with this plot, including "..." and "...", which I disregarded because of ... and ..., and two tricks have caught my eye are Greed and Visi-bill. Would you recommend one over the other, or are they pretty similar in difficulty and reactions? I live in England so my money's different sizes. Does that matter with any of the tricks? Will I have to destroy any of my money? Are there any other tricks of this nature that I haven't mentioned that you would suggest I take a look at?" will get you much more detailled answers because you have mentioned your skill, where you'll be perfoming and to whom, reasons for looking into the tricks, tricks I don't like and why, factors that may affect me like having different sized notes. With a post like that I can almost guarantee that I'd get both a detailled and helpful response, rather than have someone tell me to "do a search".