The best way to use this cement is not with the applicator brush in the cap. This brush is far too large and clumsy. Get yourself a fine point paintbrush (eg. a 00 or 000) and reserve it just for this purpose.
Brushing the cement on one part and pressing the two parts together won't necessarily work - this cement evaporates very quickly, and this method may result in a poor bond.
The best way to use "thin" liquid cements is to hold the two parts together and touch the loaded brush to the join. The cement will flow into the joint by capillary action.
Take care though, because a little goes a long way. In the same way that it will flow along a seam between close-fitting parts, it can also flow along molded details (or between your fingers and the parts you're holding).
For some applications, such as intricate sub-assemblies, or near parts which are to be left moveable, thin liquid cements are not ideal. For this sort of application, a thicker, less flowing type of cement is preferable.