I did part of mine with farming the Hephaestus adventure. There are fair number of videos on how to do it. There is also another farming method on Nessus ("Hallows" location) I also went into the Lost Sector on Mercury and farmed the last 20% (200) kills and was getting about 3% increase each loop. Honestly - that was perhaps the easiest and less stressful method that I found. Most of the Vex tend to bunch up and so it's easy pickings. Kill the adds and don't bother with the boss. Just run out, rinse and repeat.

Head to the beginning part of the raid solo, and wipe out the cabal in the courtyard, they spawn infinitely. Shoot 3 once each, then headshot one, and they should explode, and just keep doing that. They group up a lot so you can get a decent amount of explosion kills as well as the normal kills.

There was a YouTube video about doing some catalysts without people being around. They said to change your date to the day before and nobody will be in any lobbies. Start escalation protocol and your good to go. Then make sure you change date back to current date. Change the date on your console was what I was referring to.