+1 for shake and vape. If it dont taste at least sort of good right away its probably not going to get much better down the road, although it could. Some flavors do get different over time and its important to know that
for example I discovered FA whiskey weakens a bit over time. SO I take that into account with my mixes. There is some ingredient in HIC's 3 milky musketeers I think cocoa or chocolate that tastes better after a few days, but still tastes great right away. Many say tobacco flavors need to steep and can taste totally different after a few days to a few weeks. I havent done a tobacco flavor in DIy and havent even used one in years form a store so I can not comment form personal experience, just from what Ive read.
Here's how I find out if steeping helps
Once you have a flavor you like, make a couple 30-60ml bottles up. By the time you use the second one it has steeped. ANd you will know if steeping helped. If you forget the taste of it fresh, no problem remix the flavor up in a small batch of 5-10ml real quick and compare.
In my experience fruit flavors do not change,over time. waiting to see if FA black licorice tastes different after a few days,
Sometimes steeping does help with very complex blends as well, say 5+ totally different ingredients. It allows then to mix fully and blend together more.Which i think is the case with HIC's 3 milky musketeers.
Plus steeping isnt the only thing that can change your flavors. different watts, different temps, different coil types and resistances,and wicking materials all can mute or amplify certain flavors