Hello :o) I am new in here and even newer in photo restoration.
I am trying to restore my grandpa’s photo, which is already not in a bad condition.
I would really appreciate some tips on where have i gone wrong and what should i do to give it some depth especially around the nose area.
thanks

Geeez.. I'm no good at the drawing part, but here's a tip.

Use a "dodge and burn" layer above the photo with a 50% gray fill with blend mode set to Overlay. Then with a very low opacity black brush, start sculpting the nose area with shadows. Run a slight gausian blur to soften your stroked areas. Repeat as necessary.

The first picture shows the stroke areas overly exagerated. The second with a lower layer opacity as it should appear

Had a quick go with your picture. Not quite sure what you were looking for, if this is close, let me know and I'll post what I did.

Where you went wrong:
1)You didn't adjust the image (using levels or curves) first. Tlhe image is faded fairly evenly and a simple levels adjustment would bring out the finer detail you are looking for. You should only need to do some minor blemish removal and some work on his jacket.

2)You shouldn't change the background(for some reason, beginners always to that.) Unless you are experienced and very talented, it's one of the worst things you can do to an image Repair it as you would the rest of the image.

3) "If it ain't broke..." Don't rework areas that don't need it. You'll end up with a "painted" look to your image, and probably do 10 times the work trying to make it look better.

Truthfully, you should start this one over.

I thought I'd give it a try to get the face less flat.
I didn't do any restoring.

Duplicated image, used healing brush and clone tool to fix top right, adjusted levels, merged copy and levels into one layer, duplicated that layer, on second layer used burn tool to bring out nose, activated top layer and set opacity to 42%, merrged into new layerr and used color replacement tool to get rid of red tent on parts of picture. Sorry for not beiing really clear in what I did, kind of just played with it and wasn't planning on posting. Let me know if you want any details and I will try to rememberr more.

Zenia I think you over corrected the whites on your restore and one can see where you copied the foreground layer and pasted it to another layer. that may not have been necessary.

I've enclosed a screen dump of what I did to your photo:
1.) I used a levels adjustment layer and used the Option (alt on PC) on the light and dark sliders to find the light and dark points of the photo and placed the respective sliders to these points.

2.) I removed the color by using a channel mixer adjustment layer and selected the monochrome button with about 50% green and 25% blue and no red

3.) I then created a stamp layer to combine these layers to a new layer

4.) I then made a clone layer to clone out the tape on the upper right hand corner of the photograph

5.) I then made another stamped layer to continue from there

6.) I ran a neat image filter on the photo to remove grain

7.) I then placed some tint back into the image with a HSL adjustment layer.

There is more work to be done on the irregular luminosity using a technique described by Swampy.

You may wish to sharpen the image some after correcting the luminosity