Opinions vary based on the input text, but the English letter frequency list I use starts ETAONRISH in descending frequency. Based on that, coupled with a little bit of insight on English words (as opposed to random collections of 5 letters) I've ended up with ALIEN, STORM, CHUMP as my regular first 3. Sometimes I deviate if the earlier rows offer insight, and sometimes I swap the first 2 based on a whim. And unless…
Guess all the vowels early. TRADE and PIOUS is how I usually do it, but ALIEN may be a better starter.