Don’t tell anyone – Work on a “need-to-know basis”, but remember: no-one needs to know. Keep work friends out of the loop.
Don’t change your attitude – Any manager worth their salt will be highly attuned to subtle shifts of attitude in their individual staff members. Whatever your normal attitude, don’t change.
Don’t change your behaviour – A sudden day off for a spurious reason “I ran over my cat in the driveway” – is the classic sign of a secret job hunter. Find a believable reason why you might need time off in the future and feed it into the conversation now. When the time comes for time out, no one will twitch. Don’t take calls in the office and then step outside to talk, unless you regularly do this anyway.
Don’t leave traces at work– Don’t use your work computer for browsing job ads, agencies or checking your messages and emails – network logs show history and your IT department can get around your passwords. Don’t assume a separate meeting room is in fact private and secure when you have to do those skype or phone conversations.
Searching for a job while employed requires you to tread lightly, be patient, and stay discreet!