If travelling abroad, get insurance for medicine and travel disruption, buy with a credit card and book with firms that are members of protection schemes like ATOL.
Until you make good your escape, avoid crowds, inform family and stay in touch with the embassy and travel operators. The embassy might be able to get you on a flight, perhaps military, but may want paying back, and may dump you in the nearest safe country, not the UK. But remember embassies will close or restrict service if SHTF due to health and safety.
Read FCO travel advice and follow their alerts and the embassy.
Terrorists look for tourist hotspots on notable dates. The most dangerous flights are from Turkey, Egypt, Jordan, Tunisia, Saudi Arabia and Lebanon. Consider varying your routine and routes, plan escape routes, avoid hotspots, be vigilant and blend in.
Check travelhealthpro website two months before you go.
Keep a prescription with medicines to reduce the chance of allegations of smuggling.
Keep spare time on your visa.
Have backup copies of travel documents with friends.
Take backup funds.
Keep a bugin bag wherever you stay as you can be unexpectedly locked down.
Read up on local customs.
Avoid looking rich or imperial.
Try to learn some of the language.
Get an international driving licence and do not drink drive.
Stay away from drugs.
Do not aim lenses at things which might be misinterpreted.
If you do not want to be tracked by state security, do not use hotel stationery or any dry cleaners as they will be dyed for tracking.
Do not try to evade tracking or bugging once it happens or you look like a spy.
Never sign anything you did not ask for.
Remember embassies try to limit help to signposting and travel documents, and try to avoid giving you money, passports, safety or legal advice or interfering in justice. Exceptionally they can give you a passport loan. They may be more forthcoming after a terror attack.