There is nothing like a good black pair of trousers for work and casual wear. I have some slim stretchy pull-on ones from H and M (above) which were an amazing buy several years ago, and a gorgeous thick stretchy pair of black Mosh Mosh slim legged tuxedo-type trousers (above). You can wear these both formally and casually, but for work they are amazing. With a nice shirt or blouse and simple jewellery you can fit in everywhere.