Just to clarify because it may not be obvious... for SSP, you want to slip 1 k-wise twice then p2tog through the back loops. The last bit is a little tricky because you have to put the right needle in from the back from left to right (which feels kind of awkward), but Amy has a video for it if you need help.
There is no right way to knit; there is no wrong way to knit. So if anybody kindly tells you that what you are doing is "wrong," don't take umbrage; they mean well. Smile submissively, and listen, keeping your disagreement on an entirely mental level. They may be right, in this particular case, and even if not, they may drop off pieces of information which will come in very handy if you file them away carefully in your brain for future reference.