First of all welcome to ELR to you both @Tracey001 and @RobertBrownieJr .
And here we go… my 2c?? I’ll sound boring and monotonous… and I apologize to all those that have seen this so many times.
Let’s start from your recipes… TFA Grape @20%??? which Grape? Candy,Soda, Natural (outsourced) or Juice? TFA’s got a few, but beside that, it’s not an easy flavour to deal with, close your eyes, bite e grape and think about what you taste and feel, define it…
Definitely TFA (IMHO) doesn’t even go near, (believe me I have got 6/7 Grapes and got rid of TFA years ago… I had the candy one) FLV, Chemnovatic, INW are my go to, for a greenish Grape I go with layer of Reka and Cap Concorde… and this is to lead to the “Disposable Taste” argument, they use commercial grade flavour, Reka, Chemnovatic, and generally very strong Flavours at the “right” percentages, our latest flavours (FLV,VSO,VTA WF etc.) are more for a crafter type liquid, better defined, safer, and apt for complex mixes and layering.
Now the base… disposables are low wattage devices, they CANNOT handle high VG liquids, so it’s not unusual to even find 60 PG at the end 50/50, 60/40 (both ways either Pg or VG) are the go to, depending on the target liquid.
As you already know you can’t make complex, layered mixes, they won’t come through, 2-3 flavours at most.
Ever wondered why you won’t find custards? With Custards layering, higher power and high VG is a must, but you can use creams, milk, milkshake and vanillas, but it’s as far as you can go (don’t trust @fidalgo_vapes he cheats more than me… he used SB Milkshake layered with Honeydew… clever.) and that’s another hint, use flavours that are already layered, Forest Fruit, Nut Mix, SB Milkshake, Banana custard/ Nut bread, CDS and flavours that are known to “come out” Blueberry, apples, licorice, Peaches.
Additives:
Sweetener, with rebuildables we always care about our coils and gunking, “theirs” get thrown away… so who cares if they last or not, plenty of it (based on our standards… that is 0,5, 0,75) unless you use sweet flavours.
Cooling agents, they are used everywhere, use it with care, but it’s cheating, it’s easy to hide a poor mix with lots of sweetener and ice.
AP, triacetin, Citric acid, Malic Acid all used to balance the mix use them with knowledge and care
Muting, is a complex discussion, generally avoid over flavouring, sometime over flavouring is not just the simple percentages too high, but also molecules used inside the flavours, as a silly example see this one:
Strawberry sweet and ripe, Bavarian cream, milkshake, vanilla swirl maybe even pushed on the high side (Old style like) you know what?
It’ll mute! Even if used at the “right” %, Malt and butyrate are the main culprits, those are molecules all used “inside” the flavours and added up will result in over flavouring without you even knowing! The Battle of the titans…
Can layering be done? of course it can, if the aim is to reach a single flavour… e.g.:
This one is relatively complex, but you can see that the layers are aimed to build a single flavour to make it stand out.
Start with easy recipes, don’t even look at recipes with 7-8 flavours, they won’t work on a POD, unless it’s aimed, (rarely) also beware of recipes that are over 25-30% , unless inside those mixes you see Distilled, NETs, and natural flavours, those typically can throw the percentages off, stay away from them.
Alright, boring as usual, just some hints but a lot on your plate to dig in and enjoy…
@RobertBrownieJr show us your stash (put the link) and what you made, so we can help you improve.
My welcome to ELR!! 
