As a vaper myself, I feel the need to reply, but it's probably not the answer you're looking for. You've probably tried already some of the basic recipes, where one takes (decarbed) flower material or keef and mix it directly with a PG/VG base, than filter the resulting solution. The plant material should be decarbed, otherwise it won't be effective. I do believe this is a safe way of vaping, however, it isn't very effective nor efficient.
Better results can be achieved with an extraction method first, meaning you'll make cannabis oil fist and than mix it with a PG/VG base. However, extraction requires the use of an extraction solvent, like isopropyl or butane. Doing this at home can already result in increased risk for accidents, but more important: there will always be a residu of the solvent in the resulting cannabis oil. It's also possible you'll need another solvent to ease up mixing the cannabis oil in the PG/VG base.
Vaping these solvents can lead to serious harm! Do you remember all the reports last year about the 'mysterious long disease' vapers suffered from? A majority of them were vaping some form of THC liquid and it seems this caused the illness.
Dr. Farsalinos (a strong vaping defender) wrote about it:
"The culprit is not THC/cannabis per se. Most likely (but this has not been proven yet), the cases are related to other compounds used in the preparation of THC/cannabis containing liquids or contaminants in these liquids. While there are reports of vegetable oils being used as solvents (that would certainly be consistent with cases of lipoid pneumonia) or a fungicide, we cannot determine the cause yet." (http://www.ecigarette-research.org/research/index.php/whats-new/2019/274-us-lung)
Therefor, my urgent advice is not to experiment with this.
The most efficient and safest way to vape cannabis, would be to invest in a dry herb vaporizer. I'm going to buy the Davinci IQ 2 myself in a few weeks, but there are a lot more and also cheaper options.