Realia (real objects) can be used in many ways in the classroom; for example to liven up a presentation in a coursebook, to practise vocabulary and structures. Realia is very memorable for students and can serve to involve them more in the lesson.
Real objects can be used to teach vocabulary - e.g. swimming costume, tennis ball. They can be used to practise a structure- e.g. she goes swimming every Thursday, she's going swimming tomorrow, they play tennis every Friday etc. You can contrast the use of the present simple and the present continuous or you can choose to focus on the use of "go swimming" vs "play tennis". They can also be used to practise prepositions of place: next to, between, etc. They can be used to practise the structures "is / are there?" and X is made of ...... You can also use them to practise the order of adjectives - e.g. a large, brown, leather handbag.
Realia can also be used to develop a description or story - e.g. how to make a cup of coffee. They can also be used to develop a dialogue - e.g.
how much is a packet of tea?
I'll take two please
What's her favourite sport?
How often does she play (tennis)?
Twice a week
I'm sure that once you get used to using realia and other visual aids, you will find many new ideas yourself. One thing to remember is that they can take a long time to organise and prepare. However, it is worth investing this time if you think your students will be motivated.