That's a big question. There are some ideas on the site below.
Try to keep away from your common language as much as possible - you are establishing a dependency that will be hard to get rid of. I suggest you get a copy of a book like Jeremy Harmer's 'How to Teach English' it published by Longman. Also you might benefit from using a course book such as Wavelength or English File. Each has several levels starting from the beginning.
One thing you might do is go shopping etc. with your learner and help with practical English - don't do it for them just offer suggestions as to what to say to shop assistants etc. Perhaps drill things like "I'd like ... please" or "Do you have ..." Keep it simple at first.
Teaching Absolute and False Beginners ESL EFL TESOL TOEFL Students English - Discussion of Methods for Teaching Absolute Beginners as opposed to False Beginners
- For Teachers