Some people prefer to match the increases, like a M1R and M1L, same for decs - ssk at the beginning of the row, k2tog at the end. It's up to your preference. You might make a sampler of the increases and decreases and decide which would look better.
Dec at each end of the needle just means to dec at each end of the row. You can put them 1 st in if you prefer, doesn't have to be in the very edge stitch.
sue- knitting heretic