Everything you need to know about e-liquid :

The substance used in vape kits and e-cigs to produce flavorful vapor is called e-liquid, sometimes known as “vape liquid” or “vape juice.” Vegetable glycerine, propylene glycol, and flavorings are the three basic components of e-liquids. Although many vape juice flavors are available with nicotine-free alternatives, most e-liquids also include nicotine. E-liquid comes in many different “types,” but they all generally fit into a few broad categories. To choose the appropriate kind for your vape kit or e-cigarette, it’s a good idea to be aware of these if you’re new to vaping. See more information on these below.

Types Of E-Liquid
You can find a ratio of two significant elements in every e-liquid. They are PG and VG (vegetable glycerin) (propylene glycol). While PG is thinner, VG is a heavier material. The viscosity of the vape liquid and, consequently, the devices it will work best with will depend on different proportions of these elements. They have an impact on the throat hit and vapor that an e-liquid will create as well:

Larger vapor clouds with little to no throat hit are more common with e-liquids with a VG bias.
The throat hit frequently preferred by people trying to quit smoking is offered by e-liquids with a PG inclination. These liquids often emit a smaller amount of vapor.
How to Determine the Best E-Liquid for My Device
Examining the coils for your gadget is the quickest and simplest way to achieve this. You will always print the ohm rating on replaceable coils. To determine whether you should use a higher PG or higher VG e-liquid, check the metal case, look for the ohm rating, and review the instructions above.

As mentioned above, a safe bet is to choose a balanced 50% e-juice as long as the ohm rating isn’t extremely low.