Size matters
Short texts can be much less daunting and are ideal for working on micro-skills. A very short text or a short section of a longer text can often do the job of illustrating a language point or bringing up a point for discussion just as well as a longer one. Sometimes, a single paragraph might be enough. Summaries work particularly well as mini-texts in their own right; examples might be the abstract of an academic article or the executive summary of a report. If you want to use an extract from a longer text, then you could consider abridging it. Is there a complicated example or reference that could be cut without losing the flow of the text, for example?