The current most effective way to train distance is on Modified Gnarlhounds. You can use flame, shiver, or flash arrows. These will kill the Modified Gnarlhounds fairly quickly especially if there are other players training as well.
Another option is to use royal stars on the modified gnarlhounds which will make them live much longer. You will also be able to afk for a longer period of time without having to refil ammo. If you want to train shielding while doing this you can use a Spellwand to summon a Mad Sheep.
A third option that will also allow you to train shielding is using small stones on Lizard Magistratus. There are a few areas in Razachai where this can be setup. Can also use small stones on Hydras or Sea Serpents but have to be careful while training afk.
Here is a video that shows these methods:
https://www.youtube.com/watch?v=wvYgdz-TRK0