Write lyrics that come from your experiences or your heart. They will resonate better with the listener. And they'll be easier to write.
Make sure you have a catch phrase or repeated 'chorus'. This is often the source of the title of the song and it is the most memorable aspect of your song; a 'must' if you want your song to become an ear worm.
Try to end the long notes on a vowel. It is much easier on both the singer and the listener alike.
Too little rhyming will make your lyric sound clumsy. Too much can make it child-like. You might want to occasionally use assonance to vary the rhyme. Assonance is when you use only the same vowel sound, like in "game" and "plain".
If the music makes a word sound weird or hard to understand by putting the syllable accent in the wrong place, save the word for another time and use something else, even if it's just several short words.
Have fun with your lyrics and make sure the melody or rhythm match the words. A choppy, staccato song needs short, rhythmic words whereas a weaving melody will do better with liquid lyrics. The combination of words and music are what create the unique art form of a song. Enjoy getting into it and the result will follow naturally.