They both mean "a little bit" according to the dictionary. However, does the meaning both apply in V and Adjective?
i.e. V + 一点儿/一下儿 (吃一点儿/吃一下儿，快一点儿/快一下儿) and Adj + 一点儿/一下儿 (美一点儿/美一下儿, 好一点儿，好一下儿)
In the above examples, my native Chinese friend told me she rarely or even never heard 快一下儿，美一下儿，好一下儿. So my question: is there any difference of meaning and usage between 一点儿 and 一下儿?