Landscaping/pruning help

[Travis]

I have some very large cassia bushes in my backyard that are mingling with each other along with some other bushes that probably need to be taken back a bit.  I believe this is the time of year to do it, but is there a technique to it? How far can I should I take them down?  Is there a preferred shape?

[Fishindude]

Looks like you're in a fairly dry climate so I can't speak about those particular plants.  In the midwest, you could cut back any shrub like that down to about 18" tall sticks and if will come back full in a year or two.

[RetiredAt63]

Google is our friend, I found this:
https://homeguides.sfgate.com/trim-cassia-43532.html

[Travis]

Google is our friend, I found this:
https://homeguides.sfgate.com/trim-cassia-43532.html

I went to Google first and read that article. It seems more focused on the plant being young and in need of special attention.  My plan is to knock them back so that they don't need to be touched again for a couple years.

[Travis]

Borrowed my neighbor's hedge trimmers and got some advice from my landlord.  It turns out that back corner had six bushes.  The middle-right bush is actually three spaced about 12 inches apart.

What do you think?

[RetiredAt63]

They look a lot better.

How much dead wood do they have in the middle?  This is a good article about rejuvenation pruning for severely overgrown shrubs.
https://www.azplantlady.com/2013/03/spring-cleaning-severe-renewal-pruning.html

I've done semi-severe pruning for mock orange and lilacs, where I took out about 1/3 of the largest stems close to ground level for 3 years, and the new growth was a lot healthier.

[Another Reader]

If the Army gig does not work out, you may have a future in desert landscape maintenance!

[Travis]

If the Army gig does not work out, you may have a future in desert landscape maintenance!

While I don't plan on retiring in Arizona, spending my time taking care of a garden is high on my FIRE to-do list.  Those shrubs aren't my responsibility after this summer, but I'm trying to leave the yard in the best condition I can.