Which Soundcraft mixer?
In any case, the answer about using balanced connections and leads if possible is good.
Don't be taken in by super expensive oxygen free gold plated unidirectional cables. That's just audiophool snake oil. It's not a question of a minimal difference in sound quality...it's down to NO difference.
When a pro studio is being built, they don't use boutique pre-made cables. Instead the cable is bought on reels, 500 or 1000 metres at a time and hundreds of connectors at a time. These are soldered on in situ--and I can guarantee that, while decent quality stuff is used for reliability, none of it has the sort of gimmicks you find in music shops.