--These Issues may or may not apply to you, but these are things im noticing and my own solutions, if you have a different solution or tweak my approach I would like to hear it
1) Wintergrasp Imbalance - Alliance wins the majority of the time, it feels hopeless for horde unless guilds really want to do Vault of Archavon. This could swing in the favor of Horde as well, and alliance could stop chaining wintergrasp wins because....player perception is everything, and if players dont think they have a chance, they wont queue, numbers win Wintergrasp.
Players look at Access to Vault of Archavon as the biggest issue, I think players forget Wintergrasp is an extremely good place for farming Eternal materials for the winning side, it also gives tons of honor and access to a PvP vendor.
The biggest issue is player perception, Horde HAS the numbers and geared/skilled players, they just dont queue consistently because they think its pointless.
2) Battlegrounds Imbalance/Queues - One side will often have better gear/players. (Anecdotal) 70% battlegrounds ends with a dominant side, and half the players on the loosing leave before the battleground ends. Additionally when battlegrounds are lopsided, one faction has many players sitting in queue, unable to play PvP because the other faction is no longer queuing.
3) 2x Honor Points - makes grinding pointless for veteran players, while battlegrounds dont pop as often as retail, theres enough wintergrasp/battlegrounds for new players to get the 1st Tier (Savage Gladiator) decently fast and have a good starter point. However Veteran players will quickly cap 75000, buy all the mounts, and still keep running into it, it feels pointless to queue battlegrounds besides daily 25 arena points.
4) Low Arena queue - low queue rates makes getting some pieces hard to get. Blizzlike has you starting at 1500, and later 0 as of season 6. The server has decided 1000. While helpful compared to 0, the issue is that this server has a middling population and arena queues dont pop all the time, nor are the ladders populated with 1500+ rated teams making it far more difficult to push rating for 1600+ gear for teams that are decent, but not great and only deserve Tier 2 gear, not Tier 3.
5) 3v3 Arena is nonexistent - Self Explanatory
--My Solutions (From A to C ~~ A being my favorite approach)
1a) Introduce a loss-chain forgiveness Buff - Every loss while attacking will give a faction a buff that increases in power (Player/Vehicle Damage, Health and Healing) for each loss in a row. This will still give the dominant faction the majority of wins they deserve, while giving the loosing faction an eventual guarantee at VoA, Farming, Honor Points, and the PvP Vendor. 1b) Cap off players from queuing on the winning side - Im not a fan of this because everyone should be able to experience wintergrasp and be able to give their own shot at winning Wintergrasp rather then relying on other players for VoA, Farming, PvP Vendor. The Tenacity buffs are decent (not great, but reasonable) for covering a lower populated side 1c) Let each side have Vault of Archavon - Ive heard it suggested....but....No, earn it.
2a) Implement xFaction Battlegrounds - The Issue is that it will be difficult for devs to properly implement. I personally love it as this gets rid of issues with players sitting in queue all day, nothing feels better then an instant pop, and it reshuffles teams, giving a fresh experience with new compositions and gives a loosing side a chance with a reshuffle of teams with every new battleground. The other Issue is that it goes against the traditional Alliance vs Horde, however anyone that actually cares about PvP could care less about Roleplay and Blizzard already is breaking that standard in Retail, seeing the benifits with xFaction. 2b) Increase loss honor gains at the end of a match - Very easy to implement for devs, and allows players that constantly loose to get more gear to give them a better chance. I personally dont care much for this solution as it goes against the heart of PvP which is earning wins for your gear, and the loosing player experience itself is still quite bad and feels compounded if your forced to stay and get farmed at graveyard until the other team decides to cap the third flag.
3) Make Honor gains 1x. Cut Tier 1 gear in half, Leave Tier 2/3 the same - Honor gains feel more natural, new players still gain gear quickly, and allows veteran players push honor points who DO love grinding battlegrounds.
3 - (Optional) Increase Tier 3 Honor Items - Make Tier 3 items more expensive, Each new season makes Veteran players spend more time in battlegrounds grinding out the Tier 3 Off-Pieces.
3 - (Optional2) Make Librams/Totems/Relics Honor - These items are for the most part, worthless and a waste of Arena points, some servers have decided just to make them honor points, this is another area where players can sink honor points into. I dont really like this as its not blizzlike, but it is a minor change that only matters to 1930+ rated players.
4a) Make certain items lower rating requirement (two or three) - Add a few fishhooks to get those 1000 rated teams that queue 10 losses or very low skilled arena teams a reason to keep queuing and push for a 1200 or 1400 off-piece item. Dont reward players with Tier 2 easily, but give high loss teams a reason to keep queuing for a reachable goal. Player Perception is important, teams wont queue more then 10 games if they dont think they will get an item.
(Personal Recommendations: 1100 Neck, 1300 Tier Gloves, 1500 Belt)
4b) Make certain items lower rating requirement (many) - An alternate, im not as big a fan as you gain more for a win then a loss below 1600 rating and players need to earn most of their Tier 2 items with a +win/loss ratio. However I know there are other players like a more smooth curve of gaining items.
(Personal Recommendations: 1100 Neck, 1200 Tier Gloves, 1250 Belt, 1300 Tier Legs, 1350 Wrist, 1400 Tier Chest, 1450 Ring, 1500 Boots, 1550 Tier Helm, 1600 Cloak, 1650 Tier Shoulder, 1700 Trinket [The Tier 3 Tier Pieced start at 1750 with Gloves])
4c) Start Arena Teams at 1500 like Season 6 - EZ change, however ive always found it rather superfluous that bad teams that loose games and drop below 1500 will constantly drop and remake teams to reset back to 1500. I really like the 1000 starting point from this server.
5a) Cosmetic Rewards - Offer pets, mounts, make the end of season rewards more compelling for 3v3 and differentiate it from 2v2. Possibly also offer Donation/Omega tokens but I hesitate to make recommendations that mess with a server's monetization. 5b) Make certain PvP items 3v3 requirement - Tricky but most popular option with many players, it can make that item impossible to obtain (if nobody queues 3v3) and players will ignore 3v3, considering the item a loss and working around it. 5c) Tournaments - In my opinion...they dont work lol, its a very short, temporary burst of activity that doesn't solve the long term issues