Hey Rich.
Hope you're not near us then! lol
Simple answer:
Polish your steeleys,
Get out your cleanest HI-Viz's.
Wash your van,
(We are cleaners after all)
and GET OUT THERE!
Look for developers hoardings or recently started groundworks.
(don't approach at groundwork stage)
Make a note of the site and then keep an eye on it.
Timing is now critical - no-one thinks of cleaners till the last minute!
A rough guide would be to approach the sales/marketing suite people (if any) first. Get friendly with them. Give them your literature (never your prices!)
If you are lucky you might bump into the site manager at the same time, but in general, don't approach the site manager until the roof is on the first property on the development (he is a busy man) He may, or may not, be thinking of cleaners yet, but he sure will need them within the next month or so.
Its about getting to know these people at the right time and getting on with them. If they like you and you look professional enough, they should point you in the right direction of the Quantity Surveyor/Buyer. (HE IS GOD!) It is He that you then "respectfully request a tender pack for the above development" etc.
IF you get a tender pack - chuck your prices back at him - and wait...... and wait... (and usually) wait...
Another way is to simply send all your literature, PLI, ELI etc. directly to head office, requesting inclusion onto their 'Approved Subcontractor List' and, yes you guessed it! wait....
Good luck - but not in my area eh! Ha Ha