When I am just out by myself eating (bill is anywhere from $6-$10), I generally start at $3 and go up from there.
I frequent a local diner/Waffle House/Huddle House type place nearly 2x week. Eggs and bacon, a BLT, a grilled cheese, plsu drink...usually a $5 tab. I always leave $3. However, the "old timers"/locals who eat there daily, leave fifty cents to a dolla ront he table. Now I realize that for their cup of coffee and egg over medium their bill is only $2/$3 dollars, but I just feel that leaving fifty cents or a dollar is an insult. It may be correct and sometimes over percentage wise, but I feel really cheap in doing so.
I no longer have to tell the waitress at the register to add $3 to my check...they now ask me if I am adding it.
When out to dinner with DH and DD, I am a generous tipper because of the mess that DD creates (she's 2.5). ALthough her messes have gone down as she has gotten older. Also if you acknowledge my child in some way (talk to her, give her an unexpected surprise, ask her want she wants or if her food is good), then you have made my day and your tip goes up. I'd rather have her acknowledged rather than grumbled about.
My husband is a horrible tipper and can never figure out the tip -- it's always too low. Thank goodness for the tip calculator that is available on cell phones nowadays.
Funny story, when DH and I were dating and in college, we'd eat out in our college town where most of the waitstaff was -- COLLEGE STUDENTS. So funny, the female waitresses would flirt with him and I could tell they were trying to get a higher tip. Funny how they never realized he had no clue how to calculate the tip and it was ME who decided upon the tip. ::::evil laugh::::: I played nice......most of the time.