How do I deal with Shasta Daisies & Lilacs?

You can dig up the daisies and split them up and move them wherever you want. At least thinning them out would help them grow and flower better. Myself, I would just purchase a small lilac bush that I like, I have never had luck with growing another bush from an existing one. If it is a hybrid, you may not get the same bush.

I agree with Nancy, but if you want to grow another lilac from cuttings, here's a link to help:

https://www.gardeningknowhow.com/ornamental/shrubs/lilac/growing-lilac-cuttings.htm

Shasta daisies are easily divided. Easiest way is to soak the clump the night before, dig up the clump, cut it into smaller chunks with a knife, replant part of the original and put the other parts where you want to start new ones. Water well and as needed for a couple of weeks.

Hi Jo! Here are some helpful tips here!

http://www.weekendgardener.net/perennial-flowers/growing.and.caring.for.shasta.daisies.htm

https://www.whiteflowerfarm.com/caring-for-your-plants

https://www.scribd.com/document/67103621/Growing-With-The-Garden-A-Curriculum-For-Practicing-Horticulture-With-Incarcerated-Individuals

The daisies are easy to separate. You can dig up the entire plant, sub-divide it and plant in various other places. Just use a shovel to split the big plant into good sized "chunks" and replant. I don't know about the lilac question. :(