- Use a spellchecker, which is very simple, use an orthographic dictionary.
- If you learn, try writing dictations.
- Remember the written form, decompose the word into phonemes and distinct them (see an example below)
Written Russian language keeps the writing of words above pronunciation and mostly keeps the written forms the same across transformations. There are several reasons: a) vowel reduction made every minor dialect have different pronunciation of the same vowel, b) written Russian came not from Russian, but from Church Slavonic. I assume that the scholars tried to keep the sacred texts unchanged. Later it became a written tradition and a common denominator for dialects.
The way functionally literate native Russians do is remember the graphical image of a word. Plus we have in mind its sources, like the base and the prefixes/suffixes. E.g.
-н- (adjective suffix)
-ый (masculine adjective termination). Now,
при- is similar to
пре- and often both pronounced with
и, but we know that
пре- means "over" and not suitable here.
Of course there are false friends like similar words that have different vowels in them, that natives confuse for related and use to check one another, like шпаргалка/шпора. But that's part of the deal.