Using coloured pencils
Coloured pencils or crayons can be a very useful addition to your sketching kit as they are light, easy to carry and don't need water bottles, palettes or brushes to create colour!
Below I have given you a few ideas for using crayons that you may not have thought about.
A few colours are all you need
You don't need to take hundreds of different coloured pencils with you when you go out. Just choose a few and blend them together to get a whole range of other colours.
Choose a mixture of reds, blues and yellows, and perhaps a green and one or two earth colours. That should be all you will need for any sketching trip. Here I have chosen a mid blue, cadmium red, a burnt sienna, yellow ochre, yellow and an olive green. With these few pencils I can create many different colour combinations.
How to mix and blend your colours
The best way to mix two colours to create a third colour is to lay the lightest colour down first and then put the darker one gently on top. If you make the strokes all go in the same direction you will get a more even blend. In these scribbles I have created a third colour (green, orange and purple) in the overlap of two other colours.
Try out your limited set of colours before you go out sketching to see what colour mixes you can create with them, and maybe even take a record of your mixes with you as a reference.
Use expressive strokes
When colouring foliage and other textured areas, use scribbly strokes that express the shape and structure, or even the 'feel'of the subject. This will make everything seem much more lively and spontaneous.
Contrast these lively strokes with flat even strokes in other areas (perhaps the sky).
Use crayons over ink drawings
If you want to quickly record some of the colours of the scene in front of you, then colour over an ink line drawing, as shown here. This will help you to remember some of the colours - albeit in a simple way.