Yeh keep your neck line and cheak lines shaved with a razor, and in the stages where its longer than designer stubble but not really a full beard, use some beard clippers or I just use a cheap Gillette trimmer
https://www.amazon.co.uk/Gillette-F...ywords=gillette+trimmer&qid=1573244267&sr=8-2
Use the number 2 or number 3 guards in the early stages to tame the straggly bits whilst allowing any sparse patches to fill out.
Once the beard is longer you remove the guard and shape the beard more free style, but for example I still use a number 3 guard on my sideburns down to just below my cheek bones.
Keeps it all looking nice and neat that way whilst it's in progress so you don't have to look like a tramp.
I've never used oil.. Had a beard for probably 7 plus years now.
If I did want to experiment with oil, I use essential oil in a burner anyway so I'd just use almond oil with a few drops of sandalwood or tee tree oil or what ever.