0. The Dodge and Burn tools.
Pluses: can target shadows, middle tones, and highlights separately. Cons: destructive editing, alters original image pixels. Easy to overdo and introduce garish oversaturated colors. The Protect Tones feature introduced in CS5 helps to reduce that problem. Recommendation: use sparingly, if at all. Best for small minor tonal corrections.
1. 50% Grey layer in overlay/soft light blending mode.
Probably the most used alternative to using the Dodge Burn tools. Easy to understand, setup, and use. And, it's effective. Paint with soft brush in white to burn or black to dodge. Use lower opacity to enable subtle changes. You can use multiple paint strokes to build up intensity of effect. Soft Light Blending mode is most commonly used. Overlay tends to work faster, but increases contrast -- works better with highlight areas that may be too flat or washed out with Soft Light mode. Overlay feels too heavy handed for shadow areas. Advanced users use two layers -- one for burning, the other for dodging. Easier to control and allows for different blending mode if desired. Can adjust layer opacity separately to fine tune. Some people use the Burn/Dodge tools on the grey layer instead of painting with the brush. That doesn't really make much difference in the end result. I prefer the brush. It's effect is faster. You need to use a lower opacity when using the brush compared to using the Burn/Dodge tools.
2. Transparent layer brush with white or black.
I don't care for this one at all. To my eye, it looks flat and painted. I'd skip this one.
3. Curves adjustment layers with hide all layer masks.
Less common than the 50% grey layer. You aren't restricted to two layers, you can use more layers to target specific areas that need separate compensation. I consider this more in the tone remapping category rather than a Dodge/Burn. But, you can achieve similar results. Can avoid the color saturation increases that come with strong burn correction.
4. Frequency separation Dodge/Burn.
Basic idea is to separate the high frequency info (detail) and the low frequency info (tone) into two layers. Place your dodge/burn layers (methods 1 and/or 3) between the two to adjust tone without affecting detail. See
this article for detail on frequency separation.
5. Luminosity Painting.
See
this article. This is a variation of method 1 with soft light blending mode. The idea is to create a selection mask for a specific range of tones and then use that to paint in the corresponding area of the 50% grey layer to precisely control the tonal range and areas of the image to adjust.
In addition, as far as tonal mapping goes, you might also want to consider using the Shadow/Highlights adjustment. CS5 allows you to apply that adjustment to a smart object to avoid a destructive edit. The basic defaults are heavy handed. Check the "show more options" box to get access to additional controls. Tonal width is especially useful.