Open a photo with a bread slice and if it is not toasted(it is recomanded not to be toasted) .

Go to Image - Adjustments - Color balance and do the following settings.

Shadows: 30;0;-15
Midtones: 45;0;0
Highlights:20;0;-10

You can make another settings it depends on how is your bread looking.

Now duplicate this layer .
Draw a logo or choose Custom shape tool and choose a shape from the list. I choose Hedere 2. For this shape you need to go to Blending Options and for Stroke set 2 px and color braun.

bread

Now merge the 2 layers , the one with the shape and the Copy of the bread.With the Magic wand tool select the Hedera shape and delete its content.

NOW it is time for a little inspiration…take the Burn Tool and brush 15, range: shadows, exposure: 10% and start burning the lines of the Hederea shape. Do this many times until it starts looking like toasted bread. Remember that the toasted bread it is not equal so you burn in some places more in some places less.
Go to the other bread layer and burn a little…you can also dodge the both layers to create contrast areas like i did…

Now as you can see we have a nice hedera logo on the bread but its shape is too obvo=ious like it was drawn not toasted. So go to Filter - Liquify - and with the Forward Warp Tool , brush size 7 , go up and down making the hedera shape not so obvious.

Ladies and gentlemen and rokesoke( :) ) the final result:

Toasted bread photoshop

Toasted bread photoshop