This is a copy/paste from this reddit post which is written by owner of lvl 90 thief:
- Harvest everything you see, you get 0.5% to 0.65% (for comparison a mob gives 0.125%) of the area level in xp when you do this (0.5% of your level in WvW), it’s always worth it to go out of the way to get these.
- Try to not level crafting skills till you get to level 50+, the content becomes harder and there are less hearts to complete while crafting xp stays the same (its % level based).
- Do WvW but only to get full zone completion, I managed to clear full zones in under two hours for close to a full level at 80 (includes the awesome xp from gathering). Even without doing the zone completion WvW is amazing xp if you gather every harvest node you see.
- Cooking buffs are amazing, not only do they give you bonus xp but they give great stats/boosts. Itt’s very easy to get your hands on food (a lot of vendors in lions arch have them), if you want super cheap xp boosts get a bag of rice balls from the cooking trainer (costs 25 karma) and give you 250 minutes worth of xp boost (be warned it deposits on depositing all).
- Try and level with friends or in a group/zerg as much as possible, not only does it make it so you can kill dynamic events (group ones) that you couldn’t if you were solo but it helps speed up hearts as well.
- Try and do dungeons at the right level, the xp from clearing is based of the level of the dungeon so it doesn’t scale but if you want to help a guildie or friend out I would go for it, its still decent xp and gear drops that is your level.
- Have one AoE weapon and one single target weapon, clearing 2-3 non-veteran mobs with aoe is very easy and swapping out to a single target weapon for bosses speeds things up a lot.
- Check karma vendors (hearts) for upgrades all the time, you should be able to buy one blue item every time you unlock a vendor with karma you get from normal dynamic events.
- If you don’t mind missing out on some gear try waiting till level 70+ to do full map completions. The xp you get will always be 10% of your level so it’s better to do it at higher levels when the content is harder.
- Explore a lot, the bonus xp you get from killing mobs that haven’t been killed in a while is amazing (some mobs with the bonus gave me around 1.4k xp per kill at level 80), not to mention you find a lot of things to harvest while doing so.
- If you’re solo don’t try to do hearts/dynamic events that are 3+ levels higher than you are, try going to a different zone (even if the other zone is a few levels below you).
- Personal story is not that great for xp but its a lot of fun and worth doing, if you want to rush to 80 asap I would just wait till 80 to start working on it.
- Clear farms that are in zones your level (or even a few levels lower), for those of you who don’t know about them each zone has a “farm” where there are 8-10 plant nodes to gather. This is awesome xp and rests every 24 hours so if you can’t spend a lot of time on each day and still want levels I would check out the farms in each zone.
- Don’t worry if you have to go back to other lower level zones to level, you might be a few levels under but the xp is still very good because you can clear stuff faster.
- Rez everyone (even ranger pets) the xp from reviving someone is great and you’re helping some one out.
- If you have extra mats sitting in your collection but can’t use them for your profession, spend a few silver to swap over to something else and use up all those mats for some quick xp.
- Weapon rune’s that give +(3/5/7/) damage on kill and stack to 25 are amazing for making things go a lot faster.
- Skills that give you bonus move speed are amazing to help you get from place to place faster.