A brief note on XP before discussing laning:
You gain xp when mobs or towers are destroyed near your hero and for taking Mercs. You do not have to land the killing blow. You gain no extra xp by having 3 heroes near the same xp source - it only counts once - so its important you have at least 3 lanes soaking experience on most maps, especially before level 10.
This is mainly for laning with a party, not solo queuing Quick Matches.
If only solo or duo queuing, standard 2-2-1, 1-3-1, 2-3, or 2-1-2 depending on where typical map objectives are since you can’t expect the rest of pug team to know/follow the following.
In team play, you rarely want things like 2-2-1.
Cursed Hollow: 1-1-3 or 1-1-1 and 2 roam. Tip: losing the first tribute here isn’t a big deal, don’t lose lane xp. Hopefully you’ll get an xp/level advantage and can then more easily win team fights for the later tributes. The 2 roamers can hopefully safely poke along with the closest laner so the other team has to leave lane while you don’t. Really, this applies to several maps early on. Lane/tower xp can often help you gain an advantage over the other team if they leave lane for it. Thus allowing you to get later objectives more easily and keep pushing an advantage.
Garden of Terror: 3-1-1 or 1-1-1 and 2 roam
Spider Queen: 1-3-1 or 1-1-1 and 2 roam
-by having 3 in a lane in these, you can hopefully push a lane early, gaining both a lane and xp advantage. It will also sometimes draw away a defender from your solo lane pusher who can then push harder as well.
-by having 2 roamers, they can help/gank where needed and the others will still keep soaking in lane.
Sky Temple: 1-1-1 and 2 roam. Similar plus you can have the 2 help where you’d like to take objective. Don’t need to get greedy for first two temples, focus 1 and keep soaking xp in other lanes.
Haunted Mines: 4-1 or 1-4. You want to push the lane your golem will be in so you hopefully have a tower down before it starts, thus it can push even further. Taking a tower or two should also give you an xp/level advantage which should help gather skulls in the mine. FYI, no other map’s objective is as important as gaining skulls in this one, except possibly the first golem…even then not a good idea. I’ve won this map in as little as 7 minutes.
Dragon Shire: 1-1-3 or 1-0-4 with 4 roaming between top and mid to clear.
You can get an advantage by getting a kill or two at the one shrine then send some to help at the other. This works better after level 10 when death timers last longer. Also, depending on your comp, it’s usually better to let a tank/support get creature on this or Garden map since their dps isn’t normally strong.
Blackhearts Bay: 1-0-1 and 3 roam or 1-3-1. With this map being fairly compressed it has a lot roaming/ganking possibilities. You need a lot of map awareness here or a leader who at least has it and can call out.
In all these, the solo lanes need to be conservative and/or very map aware. If you have an empty lane, be careful how far you push unless you can see all the enemies engaged with your teammates. If you’re 1v2, then you just want to hold near the support of your towers and only call for help if they’re pushing your towers/fort too hard. If your team is pushing another lane even harder than the enemy is yours, it usually is ok to lose some towers in exchange for towers and a fort.
Monster Maps in general: when you gain a terror, dragonknight, golem etc. You at least want your best specialist/pusher, like a Sylvanas, with your creature. They can take towers quickly, prolonging your monster’s life—hopefully your roamers can help out as well while solo-ers still soak lane xp before level 10. For the golem in Haunted mines, just about anytime you have a stronger one than the enemy, you want most or all your team pushing with it unless you are dreadfully behind in match and need to defend your base. In that case, you should still have one pusher with it if at all possible.
Feel free to add anything I’ve missed or argue anything you think is out of line.