Best way to level non-lead

Does scouting or hunting seem to be the best way to level up non-lead wolves?  Any additional tips on this?

It really depends on how often you're able to send the wolf out 

I've had my hunting team since EA came out and all of them are lvl9 and that's from them doing 15 hunts every day

I got my newer NBW scouts awhile later and one of them is lvl13 and the other is lvl11

So probably scouting

Yes, in my experience scouts level the fastest. My breeding male is a scout, and I plan to make future breeding males scouts for that reason.

Since my Hunters which I hunt with as much as possible are level 8~ and my two scouts that I missed some scoutings with are level 11.. I'd say scouting.

Awesome, thanks!

Scouting is the best way to gain exp for non-leads! Exp gain increases with proficiency for both roles, and with the difficulty of the biome for scouting or size of the trail for hunting. 
Do keep in mind that the biomes do have stat requirements, most people don't have any issues with any but the last 2 (Glacier which needs 101 wisdom and Rainforest which is 101 strength).

If you finish the map you can still gain exp from rescouting, which also have the same chance of gaining stats and brings back 2 amusement items. 

edit: beaten to it lol. Hope the extra info is useful tho :)

Scouting by far generate more EXP. 

Currently my hunters receive on average 250 EXP per hunt at the rainforest. I use up all 10 hunting slots per day, that would net them 2,500 EXP per day.

Currently my Lv 19 scout receives on average 1,450 EXP per rescout at the rainforest. It takes 1H40M minutes per rescout and 2H30M for energy regenerate to 100%, so it takes 4H10M for 1,450 EXP. Say I rescout 3 times a day that would be 4,350 EXP per day. Now because my scout is high level, the EXP gain may be skewed, so we can take a look at my lower level scout Lv 14. She receives 1,100 EXP per rescout at the glacier. At 3 rescouts a day she would get 3,300 EXP per day, which is still slightly higher than the hunters. Obviously, since there aren't a limit on the number of times scouts can be sent out, the more you send them out the more EXP they can gain over hunters.

Now my preference with leveling is scout because it has the least restrictions if you use guarana. I've been using guarana on my higher level scout for about a week and I've been able to gain ~8,000-10,000 EXP per day depending on the number of scouts I can fit in. I will be able to level her up to 20 before her next heat and breed with my lv 20 lead for some high stat pups without using outside studs.

Excellent write-ups, thanks you guys!