You can do either. Some people will actually mix them in the bottle beforehand using whatever ratio they feel will work best but usually you just spray one after the other. You can layer them on the same spot or spray them to different parts/areas of your body.
The mixes work slightly different for everybody based on factors like age, ethnicity, blood type, etc. so it’s suggest that new users start out by finding their ‘sweet spot’ with each individual pheromone before mixing them but that’s all up to you. Here’s some more info about finding your sweet spot: How to find you sweet spot…
I would also second the recommendations for CTTM2 and A314 that Clint added. They’re both very good.