How to get dual citizenship

Hi all,

I'm writing a story for the Telegraph on British people who would like to get dual citizenship with another country, and am looking for experts who can help explain the process and give some advice to readers - the more detail the better!

My questions are:

• What are the pros of dual citizenship? (These can range from the serious to the more jokey ones - e.g. can you skip the non-EU line when you go on holiday?)
• Are there any cons of dual citizenship? (Does it hold you back in any way? If you want to keep it, are there certain commitments you have to make? Any risks?)
• Which countries allow Brits to get dual citizenship?
• How would someone go about getting it?
• What are the main countries that are popular for Brits to get dual citizenship?
• Please can you provide a brief overview of the rules for the most common countries? (e.g. do some allow it if you get married to someone from that country? or do you have to live there a certain number of years?)

Thank you so much in advance,

Imogen