If you don’t have a coursebook You need to find out what the students need to achieve the goal. You have to find out what they want and lack. And you could do that through a questionnaire or an interview. If they are lacking good syllable pronunciation, do a bit of syllable pronunciation in the lesson. If they need to write essays, do a bit of essay planning. Find a text or listening clip online. Then around that listening or text, you can do some vocabulary work, grammar work. It could be some questions about tenses, sentence structure. Whatever it might be that they sort of lack or need. Or vocabulary — find some new words that they can learn. You do some activities where they match the words, do some spelling activities whether it might be around things that are in the text. And then you do some sort of productive activity where they then carry on the text.