The "Turn Around Rule Trick" from IM van Wijgerden
IM Cor van Wijgerden is one of the most important chess trainers in dutch chess history. He developed, with Rob Brunia, the Steps method, which is still used in many schools and chess clubs to teach chess to mainly children and get them towards a certain chess level.
Van Wijgerden had a few well known chess students in the past like for example Jeroen Piket, Dimitri Reinderman, Erwin L'Ami.
One of the things that Cor van Wijgerden would show his students in the training is the Turn-Around-Rule.
Does a variation that you are calculating not give you the desired result you had in mind ?
Try turning around the move order !
I had to think about this rule in a game I just played.
http://www.chessdom.com/chessity-launches-new-features-as-im-cor-van-wijgerden-is-awarded-the-euwe-ring/ (Award ceremony, with photos, and testimonials from GMs)
p.s. Note that I just wanted to share this van Wijgerden rule with you, dear reader. The game example was not a great example because after the game Stockfish showed that my initial thought of 17.Nh4+ was the best, except after 17...Kh5, white should play 18.f2f3!! and then the strong checkmate threats by white will force black to lose material. Still, I was happy to come across the rule again. If you have a better example of this rule in use, please share !