I'll assume you meant TFA/TPA flavorings.
You need more flavors to work with IMO.
Apple is quite mild to me so you may need to go 15-20% to taste anything, but it's not one of their better flavors.
Grape should be good at around 10-12%, but may not be the "type" of grape you want, as most are usually like grape pop or candy.
Forget the Sour until you've got the flavoring percents down to what you like first, then add small amounts, like 1-2 drops.
I use this, and it has some recipes included:
eJuice Me Up - Best eJuice Calculator
Just some of the better TFA flavors:
Blueberry Wild 10%
Orange Cream 10%
Root Beer Float 10%
Vanilla Swirl 1-4% (as an additive)
French Vanilla 1-4% (as additive)
Sweet Cream 1-4% (as an additive)
Brown Sugar Extra .5-2% (additive)
Graham Cracker Clear 1-4% (additive)
Cheesecake (Graham Crust) 1-5% (additive), or +10% (main flavor)
Marshmallow 1-4% (adds some body, moisture, and sweetness)
Stay away from any Cherries, Raspberry, Strawberry, and Chocolates to start out with cause most of them suk IMO.