When you add color into the equation you'll have to deal with saturation when using dodge and burn, these are the setting I normally use to keep it in check:
Dodge tool
-Highlights 5-15% increases the saturation a lot
-Midtones 15%-30% increases the saturation a bit
-Shadows depends decreases the saturation a lot
Burn tool
-Shadows 5-15% increases the saturation a lot
-Midtones 15%-30% increases the saturation a bit
-Highlights depends decreases the saturation a lot
90% of the time I only use midtones but if I want something very bright I use dodge with highlights selected or if I want something very dark I use burn with shadows selected, the inverse settings I use to decrease the saturation in some areas, you can also use the sponge tool.
In this case I used dodge in the middle with a big brush 90px and used burn in the areas closer to the edges. With a smaller brush I burned the area beneath the straps and dodged the edge close to the center I also burned the area between the two highlighted areas.
STEP 5 - straps
Now you'll be dealing with every strap separately (I'll get to the cloth beneath later). For the strap I use dodge with a medium brush at midtones in the edges and then a very small brush 1-5px with 100% hardness set at highlights and highlight the edge even more, close to the edges use the burn tool with a small brush as to kind of outline the highlighted areas. Set some general highlights and shadows in the same way you did the layer beneath.
STEP 6 - Cloth
Do the same thing with the rest of the straps, if you have some drawing experience it will be easier for you to set the shadows and highlights correctly, it comes down to feel and having some good references. For the cloth I pasted one of Marcel's fabric patterns (13 I think) but any cloth pattern will do, resized it and set the layer to overlay and opacity to 40 %. You can now merge the cloth layers (ctrl+E) or stamp the layers, select the layers and type ctrl+alt+E, and dodge/burn some areas you think need it you can also sharpen some key areas a bit.
STEP 7 - leather
What I do now is select every layer that will be made of leather, stamp it (ctrl+alt+e), in the new layer with a 1px dodge brush I go crazy with the mouse which will add some scratches. Now I will paste a leather pattern and set it to overlay 40%, this will also affect the cloth layer which I don't want so I click the thumbnail of the stamped layer, this will make a selection around it and right click with the select tool and press select inverse and in the leather layer press delete. I also did some brightness and contrast adjustments but you don't have to.