trollies_r_go,
If your trousers really need a press, wet a cotton cloth (eg tea towel), wring it out and lay it flat onto the fabric, then place the iron onto the cloth. This helps in avoiding the 'mirror' effect. The moisture also helps to shrink the fabric back into shape.
An iron should never be placed directly onto woolen fabrics.
You could also try hanging your uniform in the bathroom while you take a hot shower. The steam does wonders.