Take this type of cutout of plywood. Now frame your design on watch. I will share you the details of the shop that i know.

Firstly clean your hands properly, then take small amount of clay and shape it. Like this image and also use tools for designing for example; you will make leaf with the help of toothpick

Apply some Fevicol with brush on the flower and paste it according to your design. After this dip your Brush in water, remove extra water and brush it on clay design. this step is for smoothing clay and removing extra Fevicol.

I am uploading the address of the shop where watch cutout , colors and papermache clay are available. After completing clay work, use sand paper and rub it gently. Soften your clay work before coloring. In case, clay work will comeout or broken, don't worry it will easilly pasted with the help of fevicol. Now apply 2 coat of enamel paint ( add 2 spoon water in 1 spoon enamel). it will enhance the quality of color. Now its a time for coloring the watch. firstly apply 2 coat of color on clay ( do not add water in color). Dip your brush in color, and remove excess amount of paint. If you use excess paint it will dry like a lumps. For shading part you will take golden color or you make lighter shade of the color

Many more designs are available or you can get them customized too.

i have uploaded few more design created with the same method.