Are you buying new furniture?
From ordering your conservatory nows the time to think about how its going to look internally, if you are buying new... its time to look at the kind of furniture you are putting where so every bit of furniture has its place using the most of your room. If you already have furniture this gives you time to consider where it will be positioned then you can concentrate on decor and accessories.
Follow the theme to your garden
I love to see plants in decorative pots gives the feeling of the outdoors, which is how you will feel once you are sitting in your new conservatory on a nice summers evening, I always think its a good idea to think about how the area outside your conservatory will feel maybe go for a similar outdoor rug, matching plant pots or a garden mirror to reflect your conservatory.
The choice is yours wood, laminate, tiles with underfloor heating, or vinyl, I would think careful about carpet for obvious reasons. Also a nice idea is to leave a cut out of your floor to perfectly sink a rug to achieve a flush fit.