How to make lyrics rhyme?

I am a composer/songwriter , although still a part-time (currently doing dayjob also).
many people told me that i’m naturally really-good at the composing music part (ie: from the melody, down to the littlest instrument arrangements).
However i’m still having much difficulty in creating lyrics, especially on how to make lyrics rhyme.

I kept looking at a lot of popular lyrics examples.

For example,
in Beatle’s song “a Taste of Honey” , how does Paul come up with the rhyming-pair “and then” and “again” ?
This is the complete phrase (1st verse):

“I dream of your first kiss, and then,
I feel upon my lips again”

also many many other examples.
Honestly speaking, up until now I still don’t know how these people can like ‘easily’ come up with the rhyming end-words ?
like for example, in this case: i would still find it very difficult to finally be able to find the pairing-words “and then” and “again” , lest to put them in the RIGHT context, and have meaning!

Please help,
especially for those of you who’re already expert or experienced in writing lyrics.