There are no "easy" answers...

Beach dollies: lots of work, but affords the freedom of not being dependent on a ramp, which in many places, means long lines and/or extra fees.

Ramp launching... Well, it's not easier unless there is no wind and the water is dead flat. Otherwise, it's tough to center the boat on the trailer, as the rear crossbar is significantly lower in the water, and your hulls will typically float over the top of any side rollers you may have. Even if you don't have side rollers, the hulls will easily slide off center as you pull the trailer out of the water.

Corrosion to the trailer due to salt water is another issue, but easily mitigated by a fresh water rinse (although, you can't reach everywhere that the salt water does when the trailer is sunk). One major problem is the tendency of hot bearings to shed their grease and injest cold water (easily mitigated with Bearing Buddies, which are not standard equipment).

Mike