Eduard has nice line of 1/48 scale Mirage IIICs and IIICJs. Their line also includes many different sets of aftermarket add-ons, including mask sets. A mask set is an excellent investment in your model, as it will save you time and grief while delivering very clean lines for your finished model.
The mask set includes pre-cut masks for the canopy, the navigation lights, and landing gear, including the line between the tire and the wheel hub.
The canopy mask provides you with only the edges of the canopy. You are expected to fill-in-the-blank, which is very simple and straightforward to do. I chose to use tape, but the instructions recommend using liquid mask. I did have a very limited amount of paint bleed underneath my tape, which I had to polish off afterwards, so using liquid mask is probably the best way to go.