There are many different things one can look for when analyzing poetry to see either differences or similarities. In particular, one can analyze the poems' structures, including how many lines there are per stanza, how many stanzas, rhyme scheme, and meter. One can also analyze the literary devices used to look for differences, including things like diction, tone, imagery, and figurative language, such as similes and metaphors. Since we are limited to space, below are a few ideas to help get you started in analyzing the two poems by Robert Frost, "Tufts of Flowers" and "Reluctance".
Structure is one of the biggest differences between the two poems. For instance, Frost wrote "Tufts of Flowers" in couplets. Couplets are verses or stanzas consisting of two lines that usually rhyme and have a consistent meter. Frost uses couplets all throughout the poem. On the other hand, Frost chose to write "Reluctance" as a lyric poem with four sextets, meaning four stanzas, six lines long.
There is also a significant difference in rhyme scheme. To figure out any rhyme scheme, we look at the last word of each line and assign a letter to the line in order to easily identify the pattern. Since the first poem is in couplets, the couplets themselves rhyme. The rhyme scheme is AA, BB, CC, DD, EE, FF, GG, HH, and II. Then it returns to FF at lines 19 and 20, which rhyme again with the words "by" and "butterfly." Then it picks up again and goes to JJ, KK, MM, NN, OO, PP, QQ, RR, SS, TT, UU.
In contrast, the rhyme scheme of the second poem is much more complicated. Within each stanza, every other line does not rhyme while every second line does rhyme: ABCBDB, EFGFHF, IJKJLJ, MNONPN.