Natural flavoring isn't healthier than artificial persé. It really depends on whether it breaks down into nasty stuff when vaporized. That is equally true for both natural and artificial flavors. Nature contains a lot of ingredients that aren't healthy for us humans. If you want to go into the science of this try to google on it.
In general a lot of us DIY'ers are using flavors that are also used in food. For example the LorAnn flavors. If you search this forum you'll find a lot of flavors that are being used in juices. So you might want to try a few of those in your 6mg base.
As for your original question: Yes, basically DIY boils down to putting a few drops of your favorite flavor into your favorite base, shake the hell out of the bottle and
vape it. For ratios etc. do a search in the forum.