This word uses the on'yomi of 自, which you learned with the kanji, and the kun'yomi of 撮, which you learned with the word 撮る. Though it's a bit of an unusual combo, you can probably guess the first one since it's such a common reading, and the second one because of the り on the end. Just watch out for rendaku, which turns とり into どり.
I took a selfie with my smartphone.
Oh, I don't have my selfie stick.
Here are some tips on how to take a good selfie easily.