All the advisers recommend it: find a way to get noticed. They're not wrong, but it isn't easy to do. They have suggestlons, of course, some that anybody could have come up with and others that nobody would want to.
"Dress in an attention-getting way." With perfectly straight faces, I've heard people advise that you dress like your character for signings and appearances. With a not-so-perfect face, I try to be politely non-committal. Maybe some can do that, and maybe it's appropriate for some books, but it seems to me inane and counter-productive. When I see an author who's dressed funny, my estimation of the quality of writing sinks. Good writing shouldn't require costumes, and while I may remember your face, it will be a reminder that I don't want to know more about you. That's not to say I haven't seen writers suggest a theme well with accessories, but I'd skip the medieval corset.
"Be aggressive in sales." There's aggressive and there's aggressive. I have no problem with an aggressive sales campaign, but I'm very careful not to come across as the least bit aggressive in presenting my book to people. Being pushy is the quickest way for an author to make me remember that I never want to buy his work. I've been told, "You''ll laugh out loud at my book." Wanna bet? Even assertive can be too much if the writer comes across like the first three letters of the word. I agree that you have to seek people out at booksignings; most will avoid the author table like the plague. I simply step up to them, ask if they'd like a bookmark, and if they say yes (and they usually do) I mention that it tells about my novel, which I'm signing today. That gives a reader all he/she needs to know to make a decision.
"Find something in your book's topic that relates to a current issue and exploit it." This isn't a bad idea, but it's a stretch in most cases. You aren't going to interest John Q. Public in your book because it has a character in it who looks just like Sarah Palin, no matter how much you think that's true. There's some luck involved in subject matter matching current events, and it can even work against you. For most of us, there simply isn't a lot to connect murder mysteries to real life. Real life is often harsher, weirder, and more sensational than anything we could make up.
So your book isn't about a currently hot topic, you don't want to wear a costume, and you aren't the type to shove it in some poor woman's hands and demand she buy it. How, then, do you get noticed? The answer is both easy and difficult: write the best book you can and then promote it in as many places as you can. The writing part is overall the most important, because if people read a book with your name on the cover and like it, they'll look for another one. We tend to buy what we've bought before because it's safe. We tend to tell others about books we read and liked, so each satisfied customer is a small promoter-of-you.
Promoting in many areas is diametrically opposed to the first part. Writing takes alone-time; marketing takes networking. Marketing takes away from the time you'd like to write your next novel, but you won't get one if the first one doesn't sell. So learn the Internet to the best of your ability. Meet bookstore owners as often as you can. Speak wherever they'll let you. Remember the names of those you meet and what things you and they might do for each other. Do some things that aren't required, like volunteering to help at a conference. In other words, to get noticed you have to make yourself noticeable. And I don't recommend the Voldemort costume, either.