Um...well why are you actually playing the game? No offense, an honest question. I'm sure you didn't just buy it to grind dolmens. What was it you had in mind? PvP? Questing/exploring? Raiding? I'd say therein lies your answer.

You can PvP(ideally in no cp campaigns if you're below 160 cp), you can do quests(I find a lot if them very well written and enjoyable, personally), you can run dungeons(definitely can do normal ones and with some practice most vets as well), you can buy a house and spend your time designing it, you can farm and sell mats/motifs for nice profit...the question should be what do you WANT to do?

If you're looking for "what will make my character the strongest" advices, well...You'll want some skillpoints on your journey to greatness so some skyshards hunting/questing(main quests for each zone give skillpoints) is in order. If you're magicka build you'll want Mages guild leveled so lorebook hunting incoming too. You'll want Fighters guild's passives for any build pretty much but this one tends to level naturally. You'll want the Undaunted passives, especially the one providing free buff to your max resources so you'll want to get dungeon achievements down for that and/or run pledges(you can run them on normal until you're feeling confident); pledges will also give you keys to use for gear when you hit 160 cp. If you're a magicka build it might be worth it to become a vampire. If you're stamina it might be worth it to be a werewolf. If you're into sneaky things you could do stuff like Thieves guild, also level TG/Legedermain passives for better stealing and improved sneak.

In the end of the day it's simply about what you yourself want to do. Good luck

One thing that can help most characters is to make one of your daily chores, doing a delve daily for the Undaunted. It is solo, easy, fun and gives you 10 points progression in the Undaunted skill line. Even if none of the Undaunted skills are valuable to you, both passives are helpful to all characters.

Another thing to consider if you have not already done so is to expand the number of skills that are fully developed and at your disposal. My templar healer, for example, has plenty of extra skills fully morphed up and ready to slot depending on who she is supporting. I'm talking about skills that may not fit into your normal 12 slots (including ultimates) but are nice to have available when a situation may call for them and you have just a bit of notice.

Another thing to consider is possibly researching crafting traits just in case you might want to use the character for crafting at some point. And there are some other nice crafting skills that can be helpful even if you don't craft - like the one that makes food buffs last up to 20 minutes longer.

Some of this requires skill points so collecting skyshards is also a valuable activity.

The secret, I think, is to do things that feel like fun and are productive for your character. The xp will still come but perhaps it will feel less like grinding.