There are 5 quests that I like to do together when I am in Shimmering Flats. I was Level 31 when I picked them up, and got my Level 32 when turning them in.
They can all be picked up at the race track in the center of Shimmering Flats from various NPCs. They are: Hardened Shells (get the shells from tortoises); Bump in the Road (Basilisks, Crystalhides and Gazers); Load Lightening (Vultures); Salt Flat Venom (Scorpids); and Rocket Car Parts. The first four require you to kill beasts, the last requires you to pick up items around the area (car parts, of course). Bump in the Road only requires you to kill a certain number of each, while the others need specific drops, but be aware that the drop rates does seem to be better than it used to be.
If you run directly east from the track, and start tracking beasts, and work your way around the outside of the track you should be finished or almost finished all the quests by the time you complete the circuit. There are a few things to watch for though. One is that some of the tortoises are level 35, as well as some of the Gazers. I was able to take them down without any trouble, including one time when I got attacked by a second Gazer while occupied with the first.
Each time I moved into a new area, I would clear out the aggressive mobs first (red dots on the mini map), then grab any rocket car parts, and then tortoises. My bags did get full, but when I got back to the track to sell some stuff I was pretty close to the last area that I needed to go to.
South of the track is where you will find most of the Gazers; but as I mentioned, be careful not to get attacked by too many mobs at once!
Lastly, there is a gun vendor at the track who also sells gun ammo. I did not remember to write down his name, but he is there...and I did not see any ammo vendors for bows.
I adjusted my attack method slightly, and it seems very quick and efficient. I do not add Hunter's Mark, but simply get to a maximum distance from the mob and hit it with an Arcane followed by a Serpent Sting. My cat attacks automatically and proceeds to get Aggro. If need be I start backing up until the mob attacks the cat, and I then stop and let Auto Shoot do the rest. If the mob starts running toward me again, I hit it with a Concussive Shot to slow it down, and usually the cat gets aggro again. If I had to use the Concussive Shot at the beginning, and it is not back up yet, I will do a Feign Death to lose aggro. If I needed to I would be able to do another Concussive, but it never happened. And if I get low on Mana I switch to Aspect of Viper for a bit until my Mana tops up again.
By using this method I required no food, drink or bandages. The only healing was for my cat, and that only costs a little Mana. No time lost for sitting!