I always start by looking for letter occurances that fit certain patterns like a three letter word with a pattern like 5-2-7. This often leads to 'the'. Also 4 letter word that starts and ends with the same letter is usually 'that' or possibly ''else' or 'dead'. I also try the endings of longer words like 'ing' or 'ion. Also in many quotes words like 'never' or 'people' show up.
I am not a speed solver but do like a high solving percentage.