Stand up for yourselves, and if possible pick up on some industry terminology (eg query the earthing on any electrical work being done) - they hate it !
A long time ago, when I was doing my professional training (as an electrical engineer) I encountered a really stroppy Scottish foreman (no, not got anything against Scots, you've got be able to 'hear' the accent)
'So when's the boss coming ?'
I am the boss
'I'm not working for a f*ing' tart'
I am not a tart, you work for me or you get off MY site
15 years later, even though I'm a SAHM now, he still rings me as we've stayed in touch but as he says it's 'cos I had the bottle to tell him where to get off and I proved I knew my job better than most of the blokes he'd met'
I've recently been doing a plumbing job which went a bit pear-shaped and found that by dealing with the local plumber's merchant (as oppose to a DIY store) they fell over themselves trying to help me (as a token woman), but, I suspect, only because I went in asking for their 'superior' advice. I HATED having to ask for help but it saved me a fortune so I'd do it again.