Play the Angles
As mentioned, in many areas it’s illegal to power onto your trailer at the ramp. Then what? There are other options. If there’s enough space to either side and enough water at the ramp, back the trailer in at a slight angle to the down-current (or wind) side so you can angle your boat onto the trailer with the bow facing slightly up-current. This will require some finesse because you’ll have to kill the engine at just the right moment to coast it on, but angling will give you more control and better allow you to load your boat onto the trailer before the current catches and swings the stern.
If you have to back the trailer straight down the ramp, approach from down-current and keep the bow up-current — even as much as 90 degrees to the trailer — until it’s time to turn and align with the trailer. The current or wind will rapidly push the bow, so aim forward of the trailer’s centerline before straightening to quickly load up.
This is a great time to use guideposts to know where the outer edges are for alignment on approach. (Don’t have guides? Order aluminum add-ons from overtons.com)