My daughter and I found the following very helpful.
Keep a dictionary (children’s) on hand to check words that we don’t know or new words, and write them down in a note book to help remember them.
Print off a copy of the most common spelling mistakes, and frequently confused words (which get me all the time).
Spelling rules such as I before E except after C (I only learnt this a few years ago).
Homophones is handy too, as it is not unusual to confuse similar sounding words such weather/ whether. I would laminate them and keep a copy on the fridge, and give a copy to each daughter.
For reading try different coloured overlays, to see if it make reading simpler. My daughter has Irlens lenses which we noticed made a huge difference.
Learn the letters of the alphabet using bright coloured magnetic letters, and learn their placement in the alphabet, and their sounds and practice spelling basic words.

Teacher support
Teachers to write each paragraph in different colours, so students can keep track of were they are if copying from the board. (some teachers were more than pleased to do this, other not so).

For the older student, same as the above and with the following;
Class handouts to be on coloured paper, for my daughter and I its a cream or buff colour (you will have to experiment with colours).
Where possible use a computer to do assignments etc, ensuring the use of spell check to keep spelling mistakes in check.
When given an assignment start them as soon as possible, so you do a small bit each day, rather than leave it until the last minute.

I hope the information I have given will help, the last link gives you and others what a dyslexic sees when reading (I see the rivers, halo, blurry and swirl but it depends on how tired I am as to which I see).