Sometimes (particularly methods sections, or parts of introductions) you feel someone (often that senior labmate) else has said exactly what you want to say far better than you ever could. You can always quote and cite them, but after a while that gets tedious, and is less effective than writing in your own words. Here is one strategy:
1) go to the papers with things you wish to include.
2) read the sections or lines that are relevant (not whole paper).
3) close the paper, and write down what you remember that is important – keywords & phrases are better than full sentences. Outline form or list is good.
4) If you need to, but not necessary if you think you’ve got a good handle on the ideas, go back and read paper again, but without your notes! Do not write while you are reading the paper.
5) Close paper, update your notes, if necessary.
6) If there is time, wait an hour or so, or even a day.
7) Sit down with ONLY your notes, and write out full sentences of what you want to say.