These were some general principles we were taught for edexcel:
1) mention all sources in intro (quote, mention viewpoint etc.) - but do so in passing
2) lead with the sources - each 1st line of each para should have a quote and clearly show the theme of the para.
3) remember to only say relevent things
4) talk about sources together and how they agree and/or disagree
5) mention reason why sources agree/disagree (good place to bring in the nature, origin and purpose of the source)
6) miss out paras/be sketchy in them in order to get a good conclusion in
7) talk about all sources in conclusion
And remember: essay 1 -only use own knowledge as absolutely have to for arguement to make sence, and essay 2 - lead with sources but make sure plenty of specific own knowedge in there (dates, names (spelt right), places, policies, battles etc.)
Hope this helps, and good luck