You will likely have a variety of examples of text ads in the answers to your question.
I am not going to ad other write-ups.
And the reasons are as follows:
1. There are several text ads that very effective. It will depend on your target market and the language you are using to write the ads.
2. If you are using English, SFI offers some examples in the Training and sponsoring modules that you can use.
3. It may neither be effective nor necessary to reinvent the wheel. In term of text ads, SFI and its affiliates have used write-ups that have proven very effective.
You may use the ones that are available here.
This will save you valuable time you can use to place your ads, track them and monitor your results.
Then you can alternate between the available examples of text ads depending on your market and your budget.