This is for small, personal formulations.
When mixing in terpenes heat to the lowest possible temp that can get your oil thin enough to easily be stirred. I suggest between 130-150f or 54-65c. You can heat it hotter if needed, Its just best to keep it in that range because terpenes are very volatile and some start to burn off at very low temps.
Also, mini spatulas are great for getting in the corners of beakers or mason jars when mixing with or without a hotplate/stir bar. Silicone is reactive to terps so don’t leave it in a jar of terpenes and clean it after you stir everything up. I hate that its reactive… but when I can cleanly get every drop out of my jar without leaving anything behind, its worth the mild reactivity that silicone has. These mini spatulas are the SHIT. I used to use them when I was doing small formulations.
https://www.amazon.com/Tovolo-Flex-Core-Stainless-Spoonula-Charcoal/dp/B01EBZ0I56/ref=sr_1_1?ie=UTF8&qid=1536704884&sr=8-1&keywords=tovolo+mini+spatula+set
A heat gun is the quick and dirty way to heat up a small amount of product in a mason jar/beaker to get things flowing if you don’t have a hotplate. Not the most ideal but its fast. You have to be very careful and gentle when using them to avoid overheating or cracking glass. I suggest an adjustable heat gun so you can put it on a safe temp to avoid heating things too hot. I haven’t used this specific gun but its a cheap digital option.
https://www.amazon.com/Simplistex-DIGITAL-Adjustable-temperature-Warranty/dp/B0106JNHMW/ref=sr_1_4?ie=UTF8&qid=1536704312&sr=8-4&keywords=adjustable+heat+gun
A hot water bath is also another method to get it to temp, and its safer than a heat gun as long as you don’t get water in your product!
Alarm thermometers are your friend too so you can heat something and stop when you’ve reached the danger zone. This is great for larger jars of oil in water baths.
https://www.amazon.com/Famili-MT004-Digital-Electronic-Thermometer/dp/B013A81VW4/ref=sr_1_6?ie=UTF8&qid=1536950082&sr=8-6&keywords=alarm+thermometer