I'm pretty sure this is going to be complicated - entering my expenses whilst on trip abroad

I think you'll only be able to use the Money Out approach if you already know the GBP amount to leave your bank account. If you do (and it might be the easiest way), you'll just do the Money Out using the GBP details and forget the foreign currency side of it ever happened (keep the receipt still though of course).

If you don't yet know the amount and want to get it entered, you'll need to do the following:

Settings > Toggle > Multicurrency (to switch on the currency feature)

Purchases > Create (to create a bill as normal but this time a currency dropdown box will appear)

Then when it comes to paying the bill the following link runs through it:

http://www.clearbooks.co.uk/support/guides/multi-currency-2/allocate-a-receipt-to-a-multi-currency-invoice-forex-losses/