Tinting eyelashes at a salon can run you around $30, but learn to do it yourself and you can get it done for next to nothing.
Tinting does not add thickness or length like mascara does. It does, however, add color to light eyelashes making them more apparent without makeup.
A tint can last up to 6 weeks, though I usually do it every 4 to get new growth and darken the color.
I’m not a professional, but honestly, if you can apply mascara, you can tint your eyelashes.
The product I use, Refectocil, is not recommended for lash tinting in the US. However, it is sold in other countries solely as a lash tint. For example, check out this UK Amazon listing for Refectocil. I think someone probably did something stupid with it years ago and now it is not sold as lash tint here. Read the reviews here and here to help you decide whether or not you feel comfortable using it.
I use Refectocil Creme Hair Dye in Blue Black. It will run you about $15, but will last forever. I like to use the blue/black because I think its more of an intense black. If you want to use it for brow tinting though, you will obviously want to get a more natural color like natural brown.
Refectocil has its own developer that is quite pricey. I already had some of my Godefroy developer on hand, so I used that. Some reviews on amazon state that the Refectocil developer is just volume 10 developer like you can get a Sally’s for less than $2. I’m not sure how safe that is, so I would just get their developer.