What comes into play with this question is your knowledge of the strains your mixing. Most people know the two general varities ganja are classified into is Sativa and Indica, sativa being a more sedating but powerful high, indica being a more uplifting but mellow high. So depending on the strains you mix, you could come out with an interesting high. In any event, it won't hurt you, it'll only get you that much higher, hm?