Access Literacy, an Orton-based explicit phonics program, has formulated a list of 44 spelling rules. These are divided into rules for vowels, consonants, affixes, syllables, capitalization, and apostrophes.
The rules of silent final e are an excellent place to start, as they are very common:
Job 1: makes the vowel say its name (rate)
Job 2: English words do not end with V or U (have, blue) *"you" is an exception
Job 3: makes the letters C or G say /s/ or /j/ (race or cage)
Job 4: every English syllable must have a written vowel (trouble)
Job 5: when the last sound in a word is /s/ and it's not a suffix (house)
Job 6: odd job e - lengthening two letter main idea words (awe, ewe), differentiating homophones (or, ore), pronounced at one time (one, come, are)
Another useful rule is knowing when to use C vs K vs CK for the /k/ sound:
C: this is the most common spelling for /k/ (car)
K: when /k/ is followed by E, I, or Y, use K - otherwise, the C would say "s" (cake, kill, sky)
CK: used only after a single vowel that says /a/ /e/ /i/ /o/ /u/ (pack, wreck, tick, clock, stuck)
The key is this: there are approximately 42 sounds in English, but there are only 26 letters. The result is 72 spelling patterns. The 44 rules help you to know when to use each spelling pattern. Never guess again when spelling or reading a word.
If you would like to systematically learn these rules, I would be happy to meet with you!