As already stated forums can only give you opinions not answers (however the answers are often in there) However I feel there is no harm in asking for answers, however you need to reference all sources and a forum is not a creditable source and neither is Wikipedia (as a primary source, you should however see where the information has come from and if creditable reference that instead).

1. anxiety - it can lead to other problems. ensure they understand what is going to happen and who they can talk to afterwards if they have an issue. It is important for the mastectomy as there is a loss of body image and the image of being female. Let them know that there will be a nurse nearby when they wake up and what they might experience afterwards ie Pain.
2. Pain Pain Pain. If they are going to have a PCA teach them how to use it before they go in to surgery. Otherwise is there going to be nerve blocks or an epidural? Teach them how they work. When they come out of surgery let them know that analgesia will wear off and to not let pain build up, if they have pain, use the PCA. IMPORTANT note the number of demands when you do your obs, if you have 20 demands to 5 good, then the pain is not under control and must be reassessed.
3. Move. they have both had surgery to the top half of the body, there is no reason why they can't be getting out of bed post op. Esp when we get hip replacements out of bed day 1. A sore throat is no excuse to use bed pans and have bed baths.
4. Nutrition. We need food the heal. Ice cream is good for kids with sore throats but notify the diatician and get milk shakes made up (with additional fiber, minerals and vitamins). Even obese people can be malnourished. All patients must eat.

This is not an entire list. Refer to you Med/Surge text book for more ideas. Good luck.

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'Think not of yourself as the architect of your career but as the sculptor. Expect to have to do a lot of hard hammering and chiselingand scraping and polishing. - BC Forbes'