repeating.  Much of language learning is memorizing, and repetition is essential.  Do you have activities that help the students repeat the target language, so they can hear it many times, and say it many times?  

Next is movement.  Movement in a room creates social dynamics and language is a social phenomenon.  When students move they become more aware of their environment - a sort of heightened sensitivity, if you will - that increases their perceptive skills.  The input is channeled straight to the brain.  Also, we get lots more oxygen to help us think better.  Finally, it is just plain more fun.  When we get up to do an esl activity (as opposed to sitting down), I can see many more smiles.

Like a child, we can learn a lot by listening.  Unfortunately, it is easy to start listening and then give up soon because, well, simply, we don't understand it.  And we don't have to listen.  We can change that by having activities with question and answer so that students need to listen to the question, or perhaps another students prior answer to conclude their part successfully.  

Hand in hand with the listening is the speaking component, which is the fourth ingredient.  Let the students interact with each other, and exchange information.  It doesn't always have to be deep and meaningful if the target language is challenging.  

Let's take a look at an example of an esl activity the incorporates these four ingredients. The students stand in a circle with a ball.  They pass the ball around asking, "What time do you ~?"  and answering each other.  The ~ may be derived from cards (flashcards) on a table a previously brainstormed list on the board, or just out of thei heads, spontaneously (most difficult, but best practice).  They have to listen to each other, speak, they are moving and repeating (repeating listening and repeating speaking).  This is a great activity for about 3-4 minutes.  

Have fun creating more fun and effective esl activities!