Although I don't have guide poles, I retrieve the boat off neyland slipway which, on a good spring has 3 or 4 knots of current passing at 90 degrees to the slip.... when this is added to by a strong wind from the other direction, it does make things more interesting with a 2ft+ wave height, but as yet there are no scratches on the boat.
After plenty of practice of different methods in calm areas - 9 times out of 10 now I do the launch and recovery all myself, even with friends / family about to help, I find it easier to use the tried and tested routine each time. I let out enough winch line to go 2/3 of the way down the trailer and then lock it off. The trailer is then put into the water so the first rear rollers are just beneath the water (when rough it's a bit harder to judge), and the front rear rollers are just above. Yes, it can take a few attempts in the cross current and chop before getting it right (this I suppose is where the guide poles would come in nice) but once the bow is in the rollers, it won't be drifting sideways anymore. If the stern is out of true, use the engine in idle to swing it round, once straight, I leave the engine ticking over ahead, reach over the bow and hook up the winch line. If the boat is still holding solid, I then run up the trailer and take any slack before going back to the boat to stop/lift the engine. When I first had the boat, I would drive the boat up the trailer to the top, but with a constant chop of water, you invariably end up picking up stones and dinking the prop at some point so I don't do that anymore.
I did a recovery with woot a couple of years ago in similar conditions, and even with 4 of us, we ended up pulling muscles everywhere since we were trying to handle the boat onto the trailer manually in rough weather. Provided you are happy with your control of the boat and confident that your engine can go from ahead to reverse without stalling, I'd always now use the engine to get the boat into the right place. You don't need to use any power, but if required, you know that there is the power there to back you off.
I don't think I could do a retrieval from the sea with my boat most of the time here given the swell we sometimes get - the thing would just get smashed on the trailer.... if anything, I'd probably beach on a dropping tide and then winch the boat onto the trailer when it was dry.
An ideal setup would be like what the RNLI have with a nice tractor and trailer with massive guidepoles around it
I'm sure there are rights and wrongs for boat recovery, and my way is probably bad, but for 3 years, it's worked fine for me and the gelcoat is still the same as it was when it left the factory
-Alex