Get a Partner for Arenas, collect your 11700 Conquest Points and be done Gear gets upgraded to 650 automatically in Arenas, you dont need the 675 gear
I only mentioned BGs because I've seen that mentioned as a way to gear up. I don't do pvp and don't know anyone that does.
I have this same question, so I have been starting to play a lot... I tried apexis, but that takes a long time .. I don't farm the crystals, just do the daily.. Then I started doing ashran.. In ashran you get lockboxes all the time with either epics or 620 blues, I just vendor them, but when u first start you can just wear them. but in ashran there is the main raid you can get cp once a day from, then there are events that are randomly going on through the day, you get pc from these. And then there are rares, you get cp from those sometimes too.. What I just started doing is the main raid, then in looking for group, find an events group in ashran and join it. Then use the ashran helper plugin, it's hard for me to say its worth the money though. I bought it when he increased the price.. It is too expensive for what it is right now. He constantly is making it better, this is good, but as an example it just stays on the mount and doesn't dismount to help fight.. I monitor closely and never get a pst, but still.. after this method, to start you can get 3 warlord od draenor epics you can buy from the ah to wear.. just by doing ashran in one day you should easily be able to queue for lfr.. They just added support for lfr in honorbuddy, and it works quite well.. Also random events like chemical co from love is in the air drops a neck, so always be on the lookout for that.. Out of all these methods cp gear gives the highes ilvl, the other stuff I mentioned is just fillers until you can start raiding. Anyway.. Just my two cents..
If you don't PvP then the easiest way is to purchase gear from the AH. The crafted items are very cheap on my server, also with lots of people farming items in HighMaul there are decent 655 items available relatively cheap too I've found. I think I spent about 50K and my alt is 650iLvl still with heroic blue weapon and Oh, all the rest is 640 or 655 gear.