When you choose tools, how they feel in your hand is the most important thing.
When it comes to selecting tools, how they fit in your hand is quite important.
この場合、次のような言い方ができますよ。
ーWhen you choose tools, how they feel in your hand is the most important thing.
「道具を選ぶとき、手にどのように馴染むかが最も重要である」
to choose tools
how they feel in your hand「それが手の中でどのように感じるか」
ーWhen it comes to selecting tools, how they fit in your hand is quite important.
「道具を選ぶとなると、どのように手に馴染むかがかなり大切だ」
to selecting tools「道具を選ぶ」
how they fit in your hand「それがどのように手に合うか」
ご参考まで!