Reddit mentions of Liquitex 126704 Professional Slow-Dri Fluid Retarder Effects Medium, 4-oz

I'm giving this advice assuming you've never painted a single miniature before. And you know what they say when you assume, but I love donkeys.

1. Two (or more) thin coats are better than one thick.
   
2. Thin your paints: water works, I like "retarder." https://www.amazon.com/gp/product/B004M559I2/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
   
3. Plan your color scheme. Two or three test models and stripping them will take MUCH less time then deciding you hate your color scheme half way through.
   
4. Unless you have basing ideas, literal dirt is amazing for basing. I wash mine a bit to drain the super loose and small particles, then PVA and boom. EZ.
   
5. Weather your vehicles. Tamiya's weathering powder, the sponge-metal technique, typhus corrosion, ryza rust, all very good!
   
6. Have. Fun. I know right? Take your time. Don't make painting them into a chore, or you won't finish with such pride (IMO).
   
   GL. HF.

for moving paint around you can use a drinking straw, just dip it into the pot a little, then cover the end with your thumb, move it to the palette. if you're feeling fancy you can get some pipettes

I use about a 1:1 ratio on my palette, and I get a couple hours good use out of it just using a cheap plastic watercolor palette from Michael's. You can also make up a wet palette, I know a lot of folks like these.

for even longer lasting paint, or for wet blending, you can get some acrylic retarder

Thanks! I've been using liquitex fluid retarder I feel like I'm having difficulty getting the right mix. Like whenever I try to thin it more than a little I kind of get runny paint that doesn't really stick. Though it's been a little easier since I put it in a dropper bottle. Uh... tips?

(link: https://www.amazon.com/gp/product/B004M559I2/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1)

Definitely use a wet pallet! That will help a lot. But the water question is tricky and something you need to develop a feel for. Too much water and your paints will run and you'll ruin the blend. Too little and your paints will dry as you blend them -- leaving brush marks and stains at the edges of dried pools. Practice on a primed piece of plastic first and you'll eventually get a feel! The thinner the better and you might want to try drying retarder if you find that you don't have enough time to blend before it starts drying and you start ruining your model! I would recommend first setting up your wet pallet tonight (it can be as simple as a wet napkin underneath parchment paper) and trying to blend from white to black on a primed sprue. Easy, cheap, and will give you an idea of whether you need drying retardant or any other fancy gadgets!

Not bad for a first go. Check this video out for painting eyes - it's a larger scale but good concepts in there. As far as fading and blending colors goes, the type of paint you use is quite important. Vallejo model color works quite well imo and dry time can be extended with something like this giving you more time to blend colors.