Word you should not use if possible: obviously.
Here's why: using the word, especially as a response to a suggestion, is a killer of other people's confidence AND it makes the person saying the word look mean and/or arrogant. Example:
John: We may want to consider phasing out these TPS reports. They are not efficient.
Steve: Obviously. They even make fun of the reports in Office Space.
So if you say obviously, try phasing it out and replace it with something positive. In the above example, something simple that gives credit to John would be appropriate, even if John did not come up with an innovative solution. Saying obviously could kill John's confidence and Steve may miss out on good future suggestions that John will start holding back for fear of another negative response.If you do replace obviously, do not replace it with something similarly negative, like "I know".
The goal here is to use positive words.You may be surprised how replacing just a few words will go a very long way towards creating a positive perception of yourself (which is particularly valuable if you ever work in teams). Being positive makes you easier to work with and gets people saying good things about you.