One strategy that I find helpful is starting with a small word that can be used as is, or can be added to. I like to find the word "fright" then see if I can add -en to it; then see if I can add -ing to that; then see if I can add -ly to that. "Frighteningly" can get you a frighteningly big score!
Sex is also another good word (!). I find it usually stands out. Then if there are the letters -ual you can add them to the word; then if there is -ity you can add that as well. Unfortunately "sexualities" is unaccepted by the game. ;-(