What are good techniques to use in classrooms for teaching English as a foreign language?

By keeping the classroom alive through interesting and fun using the new technology as computers and progecters...

There are so many methods to apply in TEFL (Teaching English as a Foreign Language).
These methods vary according to many factors such as students' abilites and backgrounds, the syllabus taught etc.
Sometimes you need to follow translation for specific terms, which seem to be difficult to mime.
Other times the 'Natural method' works because it's a combination between the translation and the direct method.
Recently, the communicative approach proved competence and reliability.
This approach is simply answering the question (What do students want to do with English?).
Thus it includes large areas such as ESP (English for Specific Purposes), TBI (Task-Based Instruction) and psycholinguistics among others.
In short, I suggest you know your students first and depending on that determine whether to use class activities, spelling, assignments or small speach clubs.
Hope that will help.

well, the bases are Grammar and written and Oral expression, but the traditional way of teaching those is let's say less effective because the students are receiving information only, so what we need is to involve the students by giving them more space of interaction, for example when teaching a lecture of Grammar we can ask them to discuss a past event focusing on the use of the past perfect, in this way they will have a chance to improve their grammar, oral expression and history information.
to sum up, in my opinion the best techniques to use are to make the students positive learners and keep the classroom alive through interesting and fun, still useful tasks.

aiots listening of english

the best way is to use plenty of techniques such as computer programs, tv, slide projectors and don't forget the boards in order to explain an educational idea

langugae is  a combination of different aspects and different skills. Therefor, it is impossible to have specific techniques or good techniques to be used to teach language as whole. Each aspects have different techniques as well as skills.

Techniques vary according to the aspect of language and skills. it is worth noting that Techniqes also vary according to learning styles and level and age.