Menthol and Koolada is purely personal taste . As you go along the diy route you will find your own sweetspot. Regardless of what the recipe call for.Thanks @Raindance and @Adephi.
I only use recipes off the net.
It was a bit rough to say the least.
The others are decent and enjoying them so far.
I made a strawberry/kiwi mix with 0.5 koolada and 3 drops of menthol in 30ml mix. I thought it was quite refreshing summer afternoon vape. But my friend tried it and said the menthol was too much. It just shows that menthol/koolada is all personal taste.