i gotta say tho, some of the higher terpin strains like mango have a tendency to auto budder, regardless.
i just had a very fruity strain do that to me over a week after product was finalized. started seeing strands of bubbles and i was like, wtf?, as i machine vac purge and seemed impossible. a few more days and it's getting worse and worse. i have lots of pens, rigs, and oil jars so it wasn't for a few more days that i checked it and on the surface it looked as glassy and honey clear colored as at the start, but as soon as i moved it, it buddered up. all the above is good advice, no matter what, just don't be too disappointed when it happens again with this strain.
EDiT - i like to spread my oil thin on parchment, then put that in a small pyrex dish that has been double boiled to temp in another slightly less small pyrex dish, all of which go in the vac chamber.
well, i did b4 tami