I would budget in haircuts and shoes. We have 5 in our family and while none of us get a cut once a month, someone does. So I put that amount in each month just so I know it is there. I always budget for clothing and shoot high because of shoes. Since I do my budget for the next month during the last 10 days of the previous month, I can sort of tell by looking at shoes who may need them. For example, in Sept, I noticed that middle child was outgrowing his shoes. We didn't have another pair at home so I put a reasonable amount in my clothing budget for october. With a Kohl's coupon and cash, I came out $12 less than I planned so a bit left.
I know you can't plan for the truly "unexpected" so it's good to have a small "extra" fund for small purchases like haircuts and shoes.
For me, it's not hte occasional shoes or haircuts that cause me budget problems, it's the big ones, like a $400 car repair or my dryer conking out. So instead of having those in my monthly budget, I put $100 in savings each month (split it up, 1/2 for repairs, 1/2 for gifts and travel). So it's more of a safety net/emergency fund.
Good luck and welcome!