I have worked with dyslexic students every one of my 23 years experience, many of whom were new to the school system and had not been diagnosed, but were diagnosed later, due to starting with me at age 4 or 5. I used multi-sensory techniques and explicit systematic phonics instruction which was very effective, and the children learned to read with me, even before being identified for additional dyslexia support.
I taught theater at a private high school for learning different students for 12 years (references available) and found it very effective for raising a student's reading level, as they acted out what they read, and participated in creative ways to fill out the meaning with props, costumes, etc. It gave me a great perspective on the amazing accomplishments of older students with dyslexia.
Now in tutoring online and in person, I am enjoying seeing my students make rapid progress, as struggling readers latch on to the structure of phonics patterns not normally taught in school. The systematic grouping of words by phonics patterns is an approach that makes so much more sense to their keen minds, than the typical random spelling list approach found in school. I use the Orton-Gillingham Based Reading Lessons. I have the I Can Fly Program A and B for ages 5 - 7, and the Blast Off to Reading for age 7 - 13, These make Reading much easier and more effective whether the student is dyslexic or just needs to make sense of it all, allowing them to progress much faster, in a way that covers all the bases.