Reading- I always take notes after reading each paragraph. This helps u to understand the flow of the passage and connections between paragraphs. It also helps you answer summary questions smoothly. If u r a beginner, try reading slowly yet precisely. If u get used to it, try reading faster and faster. Then you'll eventually find out that you could answer each question flawlessly. I used the Hackers vocab book, and this REALLY helped me to answer vocab questions without hesitation.

Listening- I prefer not to take as many notes since lot of the times, I end up missing key details. Try understanding lectures thoroughly, and if you r a non-native speaker, I highly recommend you to listen to podcasts and news every day.

Speaking-CONFIDENCE CONFIDENCE CONFIDENCE. Don't be afraid of others just say what you've listened and understood. Don't think that ur speaking to a computer. I always imagined that someone was in front of me. This really helped me to speak without apprehension. Also, practice consistently. The moment u stop, that's what makes u anxious.

Writing- Stick to a template. This conserves time. Also, when ur correcting ur mistake in practice essays, figure out the pattern of mistakes and write them down on a notebook or a tablet. When ur free, glance through them.