Pffft my notifications for this thread aren't... notifying.
I dunno about the PS4 version but in the PC version, XP vastly slows at level 50.
The best way I found to XP, as a person who likes Space battle and doesn't mind grinding to get his levels, is to instance hop. I picked a part of the map in the Beta sector that seemed to have the easiest/best XP random space battle ..thing.. and if it wasn't up, I would instance hop until I found it.
The idea is to park yourself next to where a 'Random' space battle will always randomly occur on the map and instance hop until it pops and then run the thing and collect your XP.
For spice, always run Borg Red Alerts when they pop. Borg cubes can cough up 1k+ xp if you can solo them. This Alert is probably the best xp in the game but it has a cooldown of course and sometimes you'll pop in right as it is ending.
I don't think the Tholian Red Alurt is as good and don't even bother with Temporal Mauraders unless you just haven't been frustrated or wasted your time in the recent past and would like a good opportunity to do so. TM can just drag out foreeeeever in a too low level team (which I invaaaaariably end up in when I'm trying to xp) and nearly every time at least one person will bail without a word before it's over. I shred it in my level 60, geared, repped and spec'd out Escort and it's an easy way to farm any rep I want - it's not been good for leveling, though..
There are some mishes that give items that are just nice to have. I sprinkle those in as I level.
I was getting into full time mishing there for awhile but then I started breaking them over and over and over again so I stopped. Plus, the Rom mishes kinda turned me off. I'm really really glad I ran the AoY and further Fed mishes before making a Rom. That, was actually fun. But I still couldn't make it to 60 just by mishing. I went to the grind..
You may as well queue up for all the bonus Rep you can handle when you log on, too. That rep can really help out, and, the queues not only have other people to play with in them but they give that XP.
Would be my tips.
My Warbird finally made it to 60 this way. It wasn't too bad. But yeah, it's a definite gear change after level 50. Things move lots slower.
Good time to get started on that Rep (if you can already..) and get that out of the way for the buffs and gear. Not a bad time to start stocking up on Fleet Marks either if you can do that for Trait slots and extremely nice gap filling gear.
That sucks that there's no Doff mishes!
I think the main reason the CoH foundry was so successful was that it was highly farmable. (I didn't mind fighting huge crowds of sexah mobs, either...). Errr.. I mean... Some of the mishes had nice themes, too..
I just don't see those rewards in STO's foundry and I think this is one reason why it seems to be a lot less popular than CoH's was. I personally wouldn't miss it and never have used it since I first started playing and just wanted to run annnny mish.