I am no master mixer nor will I ever claim to be, but I do know my way around a mix, sorta

A few pointers I can give for anyone wanting to mix.
Spend time on the ECF DIY section. A wealth of information and tons of outstanding people that are more than happy to help. READ THE STICKIES!
Get a decent scale and mix by weight. Especially if your older and have a hard time seeing those itty bitty graduate lines in the mixing cylinder. Trust me on this! Ebay search for a LB-501. Thats the scale that was recommended to me and its an outstanding DIY scale. The money you will save from not having to buy graduated cylinders, syringes and all will pay for the scale plus mixing by weight cuts your clean-up to a tenth of what it was.
Get three 3" pipettes and one 50ml pourable cup. Thats all you will need for DIY by weight beside the scale.
Dont let 100mg nicotine intimidate you. It makes DIY cheaper and easier. Buy it in PG base, even if your planning on mixing max VG. Look at it like this. You want a max VG juice for your dripper. You drip 3mg nicotine and have %5 flavor in your mix. You still have 92VG/8PG mixture. PG nicotine is thinner and allows smaller drops into your mixture enabling you to hit your target weight easier.
Buy larger bottles of Caramel, Baverian Cream, Vanilla, Sweet Cream to begin with. You will use these four flavors a lot. Also Vanilla Custard in a 4ml bottle would be wise.
Pick up at least 50 10 ml bottles. You will use them a lot mixing samples. When you use them mark them with a permanent marker. A little VG takes it right off when you go to clean the bottles. When you do clean the bottle make sure they are %100 dry, including the caps before puting them away in a zip lock bag. nothing blows more than getting geared up to do a bunch of sample mixes to find your sample bottles have black mold on them
Keep a journal!!!!! Write down everything you do with mixing. Samples, larges batches, test batches. Mark down everything to include what you used, brand you used and most importantly how it came out after a week, after a couple weeks. So many times people made an awsome juice, the best known to man kind and they cant remember what they did. MARK IT DOWN RELIGIOUSLY!
If you tootle puff your mixtures can be as high as %25 to %30 flavor. If you drip or use high wattage then your mixtures will be %5 to %7 normally, seldom over %10. Wattage unlocks flavor. You dont need as much for higher wattages.
Dont be afraid to experiment!!!
These are just some of the things I learned in the last year. Hope it helps some of yall.