Recently I've been consulting a few words in the dictionary and after seeing their phonemic transcription I realized how my pronunciation differed from that of natives. The dictionary may then seem like a pretty good solution for the issue proposed in the title but it isn't - it's boring to go over random words. The best method I can think of is a phonetic reader - a book written solely in IPA symbols, but there aren't many of them out there and so they can't be the definite fix either.
So, in short, I'm in search of resources that can put me in contact with IPA transcriptions of a language - any language -, more often.