I wrote this post in response to question today and it turned into a full blown response. So I figured I'd post it as its own discussion. I'm not a veteran player in my opinion, so I'll make mistakes and leave things out. If you want to suggest corrections or edits, they are definitely welcome. Here goes...
Here's my quick guide to succeeding at Heart of Thorns.
Step 1: Play through the personal story - it helps you unlock areas of the map and gets you to remote locations without the bother of having to fight your way there. You should be able to unlock most of the waypoints this way.
Step 2: Make sure you have basic gliding - required for parts of the personal story
Step 3: Finish the personal story. You may need help to down Mordremoth. I sure did on my Elementalist main. Being part of a guild who will come to your rescue when asked is helpful here.
Step 4: Whenever you have an hour to kill, log in to GW2 and check the group finder first thing. Go to "Open World" and then select Verdant Brink, Auric Basin, Tangled Depths, or Dragon's Stand. Search through the HoT maps until you find one that has a group up of at least a dozen people or so. Join that group, teleport to the map where the blue dots indicating your new squadmates are. Once in the map, right click on one of the squadmate icons in the upper left corner of your screen - take the "join in [map name] option. You'll be teleported to the instance of the map where your squad is. Link up with them and follow them. Be sure to follow the guy with the commander tag on the map closely.
You'll get tons of map completion done this way without having to worry about being swarmed by pocket-raptors or perma-stunned and melted by snipers and who knows what else.
"HP train" on the group description means they're running Hero Points. The HPs in HoT actually give good rewards, so groups run them in trains all the time. If you join one of these trains of people, you'll down the Hero Points much more easily - they're really tough to solo. All maps except Dragon's Stand will have active HP trains running if you log in at the right time to catch one.
Tangled Depths has a big meta event called the "Chak Gerent." It involves going to the central waypoint on the bottom level of Tangled Depths in the lower right corner of the map near Rata Novus. The event relies on three separate squads of players defending three separate lanes that a Chak boss is advancing down. If any one of the three bosses reaches the center, the event fails. But if you have a dozen or so players in each lane, you can usually prevent that from happening. The lanes have different names - like "Ogre" and "Charr" and so forth. Pick a group defending one of those lanes. Stick around with everyone for the end where they blast open a big treasure chamber. The rewards are pretty good. Having a stack of Chak Acid handy will let you open all the tasty treasure chests.
Verdant Brink will have groups running the meta events on a daily basis. If you join one, you'll be running all over the map defending and reinforcing Pact camps. Crowbars are handy for opening the Airship Cargo Crates - the treasure chests on this map. Once all the locations have been reinforced enough, helicopters will arrive at various camps to transport you to different locations high above in the "canopy." Your group will usually pick one and go up there to group-fight a powerful boss creature. Rewards are pretty good and you can grind currency to unlock the Bladed Armor set.
Auric Basin's big met event involves everyone trying to destroy vinewalls while fighting and dodging massive enemies in... not sure... I think it's four locations in the central city of Tarir. Just pick a group and do what they seem to be doing, you'll figure it out. Once successful, the basement of Tarir opens up and everyone jumps down a hole to an area filled with Exalted treasure chests. You'll want a lot of keys to open all these and it's a ton of loot.
Dragon's Stand map is divided into three lanes called "North", "Center" and "South." Simple. Join a squad on one of the lanes and follow them down the lane. You'll pick up viewpoints, and points of interest along the way. The central Pact camps you manage to establish are where most of the treasure chest pods are located. You'll need machetes to cut them open. You can grab some as you go, but if you miss them and have to follow the group, don't worry. Once the map event is cleared, you'll have a chance to visit all the central camps you want in peace and open chests. The Hero points on this map are actually mini bosses, and to do them, you'll want to join the "boss" sub-squad as soon as your squad leader announces it in chat. The bosses scale in difficulty for the number of players attempting them - so it's polite to join the boss squad so the leader knows how many are doing it. Follow the rush to the end where you'll get a really cool fight against a massive floating dragon gliding between floating platforms. Usually it's best to stick with a platform rather than chasing around to other platforms where the action will probably be done by the time you get there. Once this is done, grab the final boss chest, visit the vendor who appears, and go back to all those central camp waypoints to snag pod chests. When you come back to Dragon's Stand another day - join a different lane than before and pick up different HP and PoI for map completion. The Leystone Armor Set can be acquired by grinding this map.
You'll want full stacks of basic salvaging kits for blue and green loot and a single stack of good salvage kits for the gold loot. Bag clearing becomes a bit of a logistical thing on any of these map meta events.
I was annoyed at HoT at first. Getting through Verdant Brink was torture my first time. But follow these rules and it'll be a piece of cake. I actually like HoT maps a lot now - ever since I discovered that it's just easier to complete if you make regular use of the group finder.