The most common methods for adding sweetness to e liquids tends to be either TFA's Sweetener, Capella's Super Sweet, Ethyl Maltol, also known as EM, or Stevia.
The Problem with Sweeteners
TFA's sweetener is basically sucralose mixed in PG, whilst Ethyl Maltol or EM, not really a sweetener per se, offers a caramelised roasted malt flavour. The problem with these sweeteners is that they can easily mute flavours over time. Perhaps of equal concern is that sweeteners can create 'gunk' that builds up on your coils, making them less efficient and can mean having to change wicks and wire more frequently.
There is a place for them so I'm not suggesting you avoid them completely, as we say it's always trial and error, but quite frankly there are alternative options out there, and exploring these options can improve both your knowledge and your mixes.
NOTE: For tobacco mixes, Ethyl Maltol or EM is widely used although I'd suggest you explore alternatives.
Below are some alternatives I recommend you explore. I can't give you exact percentages because some palettes require more sugar, some less. However, in any given scenario, and irrespective of the flavour profile, start with around 0.25 % and work up to around 2 %.
"I really feel that in the majority of cases, dessert and bakery mixes don't require any sweeter at all, as I tend to add things like creams, custards or marshmallow".
This is one of my most commonly used and favourite sweeteners. Depending on the percentage, it can either just add a sweetness or an actual layer of marshmallow. TFA or FA.
This one isn't broadly known as a sweetener but it works particularly well with bolder mixes such as hard liquors, coffee and tobaccos. TFA or FA
FlavourArt Marzipan is one of those flavours many don't think to use as a sweetener, but it's one of the better options for many applications. Low percentages too.
By far the best apple IMHO is FlavourArts Fuji. Excellent in tobaccos, fruits and desserts. Very strong so keep percentages low, starting at 0.15%.
Another excellent option for adding sweetness is FlavourArts Pear. Try mixing with some Apple but don't go overboard. Obviously great with fruits but I've also used it with pie recipes.
I'll include this one as it's commonly used in tobacco mixes although I frequently use alternatives.
There are other options I've not listed but here are some that are definitely worth exploring -
Ice Creams, Caramels, Butterscotch and Creams
Vanilla's and Custards
FlavourArt's Joy, Oba Oba & wOw
Flavorah's Sweetness (Stevia Based) is a new one for me, I'll update shortly but so far better than regular sweetener.
From The Table,
It's all about the juice..