LEDs IN FRONT
In my RV I have two 18' (T815) fluorescent light fixtures, with 2 lights in each one; and there is one large kitchen light with tw0 36" fluorescent bulbs in it.
One of the best upgrades I did was to cut out the fluorescent light ballast and use "warm" LED (T8 sized) white light in the front. However, I found these so bright I just installed 1 LED (T8) in each fixture.
Note: I first bought the "natural" white T815, but it was even brighter and I harder on the eyes. So IMO, you want warm 12V-30V, LED lights in your living area.
Here's the link on Amazon for $15 each, and I would order 2. But if you want to have double the light, then buy 4. IMO, you don't need them, but your light fixture will only have one bulb glowing, which isn't a problem for me, because I don't look at the ceiling very much when the lights are on!
... but you can buy 4 bulbs. ...In which case I recommend you get a 12V light dimmer.
https://www.amazon.com/dp/B01CSK6F7Q...ding=UTF8&th=1
KITCHEN LED 36"
I did NOT replace my 36" kitchen bulbs, because I only use those when I have shore power. (Why spend the money? Plus I prefer fluorescent "warm" light whenever possible in living areas.)
Note: Your RV ceiling lights run off 12V battery power. That ballast you cut out of your OEM circuit allows you to install 110V ballast. So if you buy 12V fluorescent lights for an RV, then you don't need the ballast.
BATHROOM VANITY "ROUND" LEDs
On Amazon you can order round LED bulbs, with the bayonet male ends, for pretty cheap. I ordered the "natural" color white light and these things are great... and bright... and don't get very hot to the touch. SO THATS A HUGE POWER SAVINGS.
I have 4 bulbs over my sink/vanity but I only need 2. So I put them on each end. And for the center 2 bulbs, I cut a piece of Mylar cutting board plastic in a circle to block the 12V of line, and now my old bulbs are physically there, but they do not turn on.
...And I used just 1 of the new LED round bulbs in my toilet 3-bulb vanity. Trust me, you only need 1 bulb in the toilet area, and the other 2 bulbs are now just there for looks.
This is the cheapest and most effective way to go. Plus my Amp-Hour when down from 50ah/day to more like 10ah and that's good for boondocking or if you have a CPAP and need to get through the night on inverter power. I.e., when you boondock the more AH you save on lighting can be used by your inverter to power your other 120V appliances.
Here's the link to buy 4 round LED bulbs for $16
1156 Vanity Replacement 12V or 24V LED Light Bulb for RV Camper Trailer Motorhome 5th Wheel and Marine Boat (Natural White - 4K)
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Side Note: Should you want a 12V dimmer switch for your RV, they make different styles, but this one looks pretty good to me, except the price.
https://www.amazon.com/Toggle-Style-...%2C999&sr=8-13