Sometimes, for various reasons you have to get a spider out of your house (normally at the request of a sister, girlfriend, wife or mother!).

Top Tip:

Anyway, if you get close but have trouble snagging it in your glass, try blowing on it reasonably strongly. Many spiders have a reflex that causes them to pull their legs in and hold on tight. In a natural setting this will help to prevent it from blowing away in the "wind". You now have a good change to catch it, while it sits still; also with its legs pulled in you have less chance of harming it.