Remember the Six P's
Proper Planning Prevents Piss Poor Performance!
We've all been there got the horn fancied a quick short notice meet and been disappointed when their phone is off.
That said I've read far too many negative reviews that start with "Tried to contact xxxx who I've seen before. Tried a couple of others with no luck then tried aw or viva street and saw abcd not the usual type of girl I'd normally go for but I was horny" and it all turns to rat shit from there.
Walking away a bit disappointed is better than walking away disappointed frustrated and 50 quid poorer. There's always another day.