If at first you don't succeed, try reading the owners manual.
actually I think it has more to do with getting more even wear on the blades, but I could be wrong.
I think I'm getting better and the trick to it (IMO) the penny set up on here, shallow final cuts, always at an angle and alternating.
So far, so good.
There are really two main reasons for feeding the board at an angle. The first is that the blades get a better bite when you are at an angle to the grain. It's the same effect as when you hand plane a board - the plane iron usually bites much better when you hold it at a slight shearing angle to the long grain because the edge of the blade is biting into each fiber one at a time rather than all at once. As anyone that has planed a board with a hand plane knows, it's much easier and smoother to plane at an angle -- the plane bites much easier, with less down pressure required to start the cut. These little planer blades are pricey and don't last long so you definitely want to make their life as easy as possible.
The second reason is to wear the blades evenly.
A side benefit is that if you have a nick in your blades and haven't shifted them, the "stripe" runs diagonally and off of your board rather than along the full length. Less to scrape or sand off later.
As for snipe, with my planer (Delta 13") I agree with Mcalpine. It's mostly all about support of the board. As the board is entering the planer or leaving it, there's a certain length where it is held down by only one roller. It either hasn't engaged the second roller and is totally held down to the table by the first roller (leading edge snipe) or has left the first roller and is completely being held down by the second roller (trailing edge snipe). The problem is often worse the longer/heavier the stock is. The little fold down tables on these small planers are just not very ridgid, so as the center of gravity of your board gets far away from the rollers, the force on the rollers increases. As the board is either entering or leaving the planer, the little table deflects a bit. Then, when the end of the board is only being held by one roller, the board essentially pivots up into the cutterhead. The result is a snipe.
I use roller stands on infeed and outfeed but they generally aren't good enough. So I also just grab the board and support it for the first foot or so going in and then walk around the planer and support it coming out. This helps almost all the time. I'm too cheap to cutoff the sniped ends or expensive hardwood if I can help it, so in my view the only acceptable level of snipe is no snipe. Can't get it all the time, but a little manual support definitely helps.
Short sleeves, no wrist watch or rings, or anything else that can snag on your board, please.