I would recommend that you not worry too much about getting a flick. There are people out there who will tell you flicks have ruined the sport because no one would do something like that in a "real" duel, and on and on like that, I'm not one of them, but I have fallen out of love with the flick for other reasons.
Flicks look cool and flashy, I must admit--which is why I have to throw one in every so often--but the percentage of points that you'll ever get off a flick, no matter how good it is, is pretty small compared to that of the points you'll get off of the less flashy stuff if it's executed properly. Of course you'll see people score points off of flicks right up to the world championship level, but you'll notice that first it is far from the only move in their repetoire, and second they score more points off of other moves.Especially with flicks to the back, you aren't taking advantage of the nearest valid target either when you do a flick.
That said, it doesn't hurt to know how to do a good one if the situation requires it. I am far from a master of the flick--like I said I lost my fascination with it a while ago and decided that it would be more beneficial to work on other things first--but here's my advice:
1. remember that it's not just the force with which you throw the point forward, it's also stopping the forward motion quickly. That's what makes it bend forward. Your hand, the grip and base of the blade stop, but the tip keeps going forward for a bit longer. I once heard someone compare it to snapping someone with a towel. It's the same motion at the end; you sort of stop and pull back.
2. At the end of the flick, you want to squeeze the the grip one finger at a time from top to bottom. If you've ever milked a cow, or know how to milk a cow, it's sort of like that motion. This will give it the forward snap without having to exert as much force and it will land more softly. This brings me to my final point:
3. Be careful. If you land a flick wrong it really hurts. Accidents happpen and we all understand that, but until you are relatively sure that you're landing the flick correctly practice against a wall, on a step, or on a fencing dummy of some kind. Otherwise, you may find that you're hard pressed to find bouting partners
As far as countering flicks, I'm sure others can give you some advice on parrying flicks with your blade. I prefer to parry them with distance, so to speak. If you change the distance so that you're either farther from or closer to your opponent than they anticipated the flick will either land flat, thus not scoring, or not land at all. Problem solved. However, if you make it land flat it may hurt sometimes, so you need to be willing to take that risk. Also, remember that if you take a strong parry even if the flick continues to "whip over" the top of your blade, you have essentially taken the right-of-way, so it doesn't matter that the flick lands, as long as your reposte lands in time.
Well I hope that helped.