How many radios?
What kind of radios?
If it's a couple of scanners, then what Scotty suggested will work.
If you are running any transceivers (or plan to), you may want a bigger power feed.
I've got a couple of radios in my work truck and I set up my personal truck the same way.
I ran 6 gauge wire from the battery:
https://www.amazon.com/gp/product/B00LIB5ASC/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1
A 60 amp Buss breaker as close to the battery as I could make it:
https://www.amazon.com/gp/product/B01FWMM09O/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
From the breaker, I ran the power to the area behind the seat and installed a fuse block similar to this:
https://www.amazon.com/gp/product/B01BV1MS1K/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
I ran a local ground from the body to a ground buss similar to this:
https://www.amazon.com/gp/product/B000OTJ8A0/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
I mounted a piece of 3/4 inch plywood, sanded and painted black, behind the seat to mount the RF decks for the radios, the ground buss, the fused distribution block and a Lind timer.
6 gauge would be overkill if you are running scanners. However, keep in mind future needs. If addition of future radios is a possibility, the additional capacity might be helpful.
Route all your wiring carefully. Split loom everything. Anywhere wires pass through sheet metal, use a grommet. Fuses are your friend.
Don't use household type wire, you need stuff that's designed for automotive use. The 6 gauge stuff I linked to above has the SAE rating for battery use. It'll stand up to heat, vibration and fuel/gas/oil.
Getting rid of the cigarette lighter plugs and the wire nuts will probably help quite a bit. Some cig lighter power wiring can run along with other vehicle wiring and pick up lots of RFI. Sometimes that RFI can get into the radios via the power feed and cause issues. Sourcing clean power direct form the battery is an ideal way to go.
The Lind timer (or similar products, like a Charge Guard) can be a great addition, as they can shut off radios after a set time elapses after ignition is shut off. Some even have low voltage disconnects. That can save you money in tow truck/jump start calls.
