What are some of the best accommodations for students with Dyslexia? First, it is important to understand that an accommodation is just a way to level the playing field for a student with a Dyslexia. Accommodations do not CHANGE the curriculum at all, they just change the way it is delivered. Below are some examples of effective accommodations that can be used at almost any grade level:

Oral administration of tests and quizzes(all items on a test or quiz are read aloud to the student including answer choices)
The ability to dictate responses on homework to a parent(this alleviates the frustrations of writing and spelling and allows the student to focus on sharing what they know and understand about a topic.)
The use of audiobooks for required readings and textbooks when available(When a student follows along with an audiobook, lots of good things happen. First, it can help increase their sight vocabulary by having unfamiliar word read to them. Second, when they are following along while someone who is reading at an average reading rate,  their brain will begin to read at that same rate when they read independently. Kind of like if you want to run an 8-minute mile, you pace yourself with a group that runs 8-minute miles, eventually, you will be keeping up at that pace!)
No penalties for spelling errors unless it is a final draft(spelling is one of the biggest struggles for kids with dyslexia, so allowing them to correct errors before taking a grade will help with confidence as well as will help them begin to recognize the words that they misspell most often.)
Allow required weekly reading minutes to be read by parent(When a student has dyslexia, any type of reading is torture. While the student is working to improve their basic reading struggles through a dyslexia program or other types of tutoring, do not force them to struggle through reading for 20-30 minutes every night. Instead, allow mom or dad to read aloud to them and focus more on the comprehension skills that they need. Let them enjoy the story and foster a love for what reading can give them. Once their reading gets up to speed, then they will not be behind in their ability to comprehend.)
Reduced or modified spelling lists(If the student is in a grade/class that takes spelling tests, then their word list should at least be reduced.  really it should be modified to match the phonics skills being covered in their dyslexia/tutoring program. If they are not in a dyslexia program (which all student diagnosed with dyslexia should be at one time or another) then reduce the list to only 5-7 words that have similar phonetic patterns.