If you want a garment made with a stretch/non-stretch this will be taken into account when making your pattern, it will be necessary to know this as if it's a on stretch the pattern will need more room than a stretch pattern.
Think about the way you want the garment to fit, if your garment is meant to come out oversized or true to size, it's important to consider this before cutting the pattern. If there are oversized features of the garment's design for example puffed sleeves or flared bottoms.
Think about how you want the garment to be hemmed and seamed as this will affect the seam allowance and the labelling on the pattern. Different fabrics might need or look better with different finishes and different finishes appear lower or higher quality. Some factories specialise in different types of finishings and could cost you less or more depending on the quality.
Everyone has a unique way of communicating their creative concepts, if you don't come from a creative background there are many ways of expressing your ideas without sketching. You can bring in an old garment with a similar shape or create a mood board of design elements you want to incorporate.
It's important to consider your pre-production and manufacturing budget before going to
your pattern cutter. Depending on; the complexity of the garment, finishing and materials used per garment your budget for manufacturing is going to be affected by the design choices you make early on.