you can't learn how to make a good expression, these are things that simply can't be learned. It has to naturally come.
I think, it's a bit more difficult.
Some people find the "right" expression just by intuition, others (like me for example

) have to work on it.
There are some principles, that help in finding the right expression:
1. play what is written in the sheet music. there are many indications in a score, that often are overlooked.
2. find the right tempo (very important!)
3. don't rush through the piece. The listeners should be given the chance to hear the tiniest details in the piece.
4. accents and dynamics are very important, so decide carefully how loud/soft you play every note. Absolute dynamics and relative dynamics are very important.
5. between legato and staccatissimo there are many intermediate levels. Try out different articulations to find the one that fits best.
6. some sort of non-musical imagination (images, sounds, feelings) may help as well in making a piece sound colorful and expressive