I think there could be a boarding ship with a pointed nose that opens up when logged into another ship and can close when boarding is finished these boarding pods will have endos in them and can be used for stealing cargo or taking ships from other players ( this Idea is mainly for people who would like to be a pirate.
Or maybe tractor beam (like in Star Trek).. could be used by large ships to lock on and slowly pull a ship towards them and smaller ships vs. large could reverse the beam to pull themselves towards the hull. Once contact to hull is made a hatch could open, exposing access to the hull where you can attempt to breach through. For defense against this, there are evasive maneuvers you could initiate in order to escape the beam or with enough engine power just thrust right out of its grip.
Currently, just floating up to them if they aren't moving works plenty well. Not to toot my own horn, but I boarded Kodey's multi-crew submarine and was able to take the bridge with no ship of my own or anything but hand weapons.
On a more serious note, I think that some sort of magnetic device, just so that you can stick one ship to another, will be necessary for any boarding of one ship with another. Otherwise it will turn into a mess of jittery physics making both ships explode.
@[B.A.N.G]SirCoitus @XenoCow The game currently has tractor beams and locking (magnet like) force field beams that can lock on to things. BUT it is disabled for anything that the game consideres a "ship" (for now. Namely anything with thrusters attached I believe. It is keeping us from makin working tugboats/wreckers. But it is pretty obvious they will enable it to work again on ships once they figure out how to make it only work in pvp space. So that would make boarding a lot easier. I too have taken out a few vehicles with guns and picaxe, its a lot of fun but floating over and latching on is a bit shaky sometimes.