There are 3 main cooling agents/ additives:
Menthol is the strongest cooling agent, but it has a minty taste, so if you like that minty taste, then Menthol is your best option, there are few menthols in the market, and Capella Menthol and flavour West Extreme Ice are some of the best ones. Capella version is much weaker while Flavour West is very strong.
2. Koolada (WS-3).
Koolada gives an immediate cooling sensation near top and back of tongue that peaks early on during the inhale and fades rapidly, it does not have any minty taste but some people feel a chemical/cardboard /metallic notes from it.
WS-23 is the most popular cooling additives as it has the iciest effect without any other extra or any off-note tastes. WS-23 gives a cooling sensation at the front and back of the tongue. Overall cooling effect is slightly stronger than Koolada and it does not have any minty taste. The recommended percentage for WS-23 is 1-5%.
WS-23 is more useful in fruit and drink recipes without fading or changing the actual taste and notes of the main profile.