The Paper:

 Oil Pastels are extremely versatile and can be used on a wide variety of papers depending on the effect you are looking for. Of course there is 'oil pastel paper'.....(not to be confused with the 'Ingres' paper intended for use with soft chalky pastels)...and this is usually sold in small sketch blocks. As such its very useful for sketching out in the field or doing small pieces. However, it doesn't seem to come in large sizes, which is limiting. And its not the best choice for mixed media work; its not heavy enough. So, don't be put off by the maker's designated use of a paper. The main thing to remember is that it needs a 'tooth' of texture to bind the pigment to the surface...otherwise the pastels will 'skin' off as fast you apply them. I often use large sheets of textured Acrylic paper (that is , paper designed for use with acrylic paint) which I then cut down to the size I want. It has the advantage of allowing me to apply a background of acrylic paint.  I find this adds depth and also gives me the option of scratching through the subsequent layer of pastels.

Most acrylic paper also allows for the use of masking fluid when applying the base coat.) This paper is capable of producing muted and subtle results which are otherwise quite difficult to achieve.

I also use large sheets of heavy quality textured watercolour paper. This gives quite a different character to the work, the colours tending to be bolder. The paper tends to 'soak' up the first application of pastel so that it produces its own base-coat. I also use coloured 'sugar' paper...or even the plain side of heavier wall-paper. It isn't possible to use a painted ground...but is very good for building layers of pastels and smudge-blending them togther. Of course its all about experimenting.

The Pastels:

Different makes of pastels have different characteristics and need to be mixed with care. Some are much less plastic than others ....cheaper 'student' quality pastels tend to be harder and less pigment-rich. This can result in the pastels simply cutting through existing layers rather than blending or lying on top. As oil pastels are so inexpensive, it is false economy to pay a few pence less for an inferior product. Boxed sets of pastels are great to get you started. But bear in mind that some, generally the lighter, colours will be used long before the rest. I always make sure I buy lots of spare Light Grey (very good for blending and toning colours down) and White. I also personally use a lot of Naples Yellow, Greyish-Green, and Lilac-Grey, too.

Other useful items:

 A selection of craft knives or scalpels is useful for sgraffito work or tidying up edges and details by removing excess pastel. (As well as for cutting pastels into thinner points or scraping off debris if a really 'clean' colour is  needed). Turps or white spirit in a shallow dish can be used to soak and soften the outer layer of the pastel for applying in large 'washes' over other colours. Its messy for the fingers...but thats fun as long as you don't scratch your nose!