If you have not finished eating, cross your knife and fork on your plate with the fork over the knife.
Indicate you have finished eating by laying your knife and fork parallel across the right side of your plate.
Toasts are given at formal meals.
When in a pub, it is common practice to pay for a round of drinks for everyone in your group.
If invited to a meal at a restaurant, the person extending the invitation usually pays. Do not argue about the check; simply reciprocate at a later time.