Speed Up Dreamleaf Herb farm

First step is to make sure you have your Dreamleaf Herbing skill in rank 3. You can go into your herbalism skill under you proffessions tab to see what rank you have. Here you can see what you need to do to get the next rank aswell. But remember to start with going to you’r herbalism trainer and learn rank 1.

-Enchant Gloves - Legion Herbalism You should enchant your hands to make your gathering speed faster. Alternatively, you can use Darkmoon firewater, which allows you to gather faster for 1 hour. This will work in all areas and with herbalism, mining, and skinning. Just make sure to get the right one with the tooltip saying "Allows faster gathering of resources and slightly increases your size for 1 hour." Because there are 2 things called Darkmoon Firewater.

-Comfortable Rider's Barding. is a mount equipment, you can equip this will prevent you from being dazed/dismounted while farming. You can craft it yourself with leatherworking or just buy it on the auction house.

-Stonehide Leather Barding. This is an alternative to Comfortable Rider's Barding but it will only work for 2 hours and in Broken Isles. You can also use your tanking spec if you have a class that has a tanking spec. This will prevent you from being dazed as well.

-Demonsteel Stirrups. This will allow you to herb and mine while mounted in Broken Isles for 2 hours. This is a must-have to do fast farming. (If you are a druid then you can herb in your travel form. Then you don't need this item unless you want to mine as well.)
An alternative to this item is the sky golem mount, which allows you to gather herbs while mounted, but this will not work for mining.

Dreamleaf Route 1 – Val’Sharah

The best place to farm Dreamleaf is this spot in Val’Sharah. Here you kill Vilepetal Rooter and then you can herb them. There is also some Defied Grovewalker you can kill and herb, but they have a lower drop chance

Dreamleaf Herb Farm Route 1 - Val'sharah
Dreamleaf Herb Farm Route 1 - Vilepetal Rooter

Aethril Route 2 – Azsuna

If you want to fly around and pick the herbs up, then you can do this route which is also great. 

Dreamleaf Herb Farm Route 2 - Val'sharah