To make your stencil graffiti, you need to first of all paint the background, which is white
To start, stick your stencil to the wall with some adhesive tape
To spray a design which has two colors from one stencil, start by doing the outlines with the background color of your choice, which is white in this case.
Next, fill in your design with a white background
You can choose another light color to give contrast with the primary color of your design
A tip: spray paint isn't like deodorant!
...so you don't need to use too much of it, or go over the same piece of wall multiple times. Doing so will only spoil your art
To finish, place the new stencil on the wall and paint the outlines in black, going over the white background
You can use a pen, a paintbrush, or a wooden stick to keep the paper stencil pressed as close to the wall as possible
it is also advised to wear gloves which will also allow you to keep the stencil as close to the wall as possible - whilst protecting your skin.
And here's the end result
Note that it's important that the wall is a contrasting color to that of your design
Although it's not the case here, you can also choose to draw a white outline around the design, in this case, a dog, to really set it apart from the wall.
If you want, you can complete your design adding in a few finishing touches
For this, you may need a marker pen containing black paint
Fill in any white parts as you so wish, or just embellish your design
These finishing touches are not at all obligatory, so they're totally up to you
And besides, a lot of artists, like Tatoo, prefer leaving their art works in their most raw forms