Hey Andrew, my pleasure. So glad you find them helpful. Advice to improve your skills? Read more. Write more. Speak with English speakers.
Use a software such as Grammarly to help you — and get an English speaking friend to help you edit too. The good thing about writing is it’s often better to write simply. When English isn’t your second language, you tend to say exactly what you mean — this is a great start and advantage you have over English speakers who try to sound so impressive ;)
One more thing, don’t be afraid to give writing a go. I love reading the writing of non-English speakers. The way they think and express themselves gives their writing such a unique angle. You have so much to share, there are a whole lot of people who would love to hear your thoughts Andrew.
Perhaps try short pieces first. Maybe even poetry such as haiku, I love that style. Only 17 precise words filled with meaning.
You have inspired me to write a post about this, watch this space :) Cheers for reading and hope the advice helps you.