First, let me preface this with something very important: you can treat all of this advice as SECOND-DRAFT ADVICE. It is so much easier to rewrite this kind of stuff once you have words on the page. Telling yourself the first draft is totally appropriate and acceptable.
What weāre talking about here are FILTER WORDS (and to some degree verbs of being). Yes, āthoughtā words are included. But so are āheard, saw, looked, tasted, smelledā etc.āmost words having to do with the senses.
This isnāt black and white advice; sometimes youāll use these words and thatās okay. Theyāre not WRONG. Theyāre just weaker. And theyāre weaker because they create distance between the reader and the experience of the character.*
If you want your reader to feel like theyāre experiencing the story right alongside the character, you want to cut down on filter words.
*This is particularly important with first person and close third POVs. The reader always knows whose eyes theyāre seeing through and thoughts theyāre privy to. So you donāt need to tell them āI saw X.ā Or āI heard X.ā Or āI thought Y.ā You can just jump into the action/observation as itās happening.
This is also where you want to pay attention to verbs of being.
āIt was rainy.ā Versus: āThe rain pounded against the roof.ā Or āThe rain howled like an injured animal.ā Or āThe rain tapped against the window like an anxious lover.ā All of these are inviting the reader deeper into the experience of the story by using stronger verbs and similes. And, at the same time, they stir feelings (instead of TELLING feelings). And feelings keep your reader engaged. Engaged readers keep turning pages; engaged readers become FANS.