Most start with using syringes to measure out then go into using a scale. I've been using a cheap fasttech digital scale
(this one) for a few years now and it does the job. Scaling is much cleaner and consistent than using syringes but each to their own. Word of caution about buying DIY kit is you overspend and once you realize the DIY I awesome...I haven't come across anyone who started DIY then ended up reverting back to commercial juices.... your going to respend the money on glycubes and liters of nic so buying smaller size 100mg nic(if thats your choice) and liter of each base is a good start. What flavorings are your issues but think K.I.S.S makes DIY is much easier at the beginning. Standalones of your first flavor order at 4 or 5% with a couple weeks steep to get familiar with what to expect rather than shooting the moon on your first mix then disappointment cause its not the vendor juice.
Pick then get familiar with a ejuice calculator and your on your way.
Its much easier IMO like I do is to cut your nic into 48 then use that as my nic for mixes. (freeze the rest of the nic in 50ml shots so I can thaw and serve then make 100ml 48nic at my desk)Much easier to dial into the preferred nic if you didn't buy a kit that gives you a specific nic strength base.
DIY juice being super cheap compared to commercial juice is only the perk...The are so many pro's with DIY, so many ways to go you'll realize how many cons with commercial there really was....starting with not needing to rely on the postal system anymore for your juice, making sure you have in hand all the time. Even unflavored juice with nic isn't really all that bad if it comes down to that.
I don't know if your rebuild yet but it too is something that factory coils just don't cut it. Some 28 gauge wire can make great simple building that produces great vaping.
Have a great journey...it just gets better and better
edit...been DIY for 3 years now and never looking back..still kicking myself for not starting sooner.