There are some nice fresh materials published by Chess in Schools and Communities: https://www.chessinschools.co.uk/chess-at-home
Chess Tips
| MIDDLEGAME TIPS: |
* Ignore your opponent's time pressure. Take your own time to find the best moves as you normally would. Don't try and rush your opponent - they are probably more used to playing quickly than you are and may outplay you, or set you a trap! |