As a waiter/waitress or bartender, welcoming a client and solving any doubt or request by giving him/her all the necessary assistance is simply part of the job. A part that a conscientious, professional, devoted waiter/waitress and bartender cannot miss, in order to be proud of the way he/she works.
This kind of proficiency implies hard practice and a lot of exercise to improve your communication skills, particularly in the English language.
Here you can find some menu samples and links to a list of examples, suggestions, vocabulary and expressions you can use as a basis for you personal practice.
Always remember: each satisfied client is a precious investment for the future!