様(よう)にするTo try to, To make sure to, To endeavor to

ようにする (literally, 'do things in such a way as to X') can express the idea of taking care to perform a certain action and often describes intentions or habits. 〜ようとしない conveys the opposite, not making an effort to do something. For example, 毎日野菜を食べるようにしている ('I'm making a habit of eating vegetables every day.') vs. うちの子どもは野菜を食べようとしない ('My child doesn't even try to eat vegetables.').

ようにする (literally, 'do things in such a way as to X') expresses taking care to perform a certain action and often indicates a habitual effort. In contrast, Verb[volitional] + とする implies a one-time attempt to do something, often implying the attempt may not succeed. For example, 毎朝走るようにしている ('I'm making a habit of running every morning.') vs. １０キロ走ろうとしたけど ('I tried to run 10k, but...' implying 'but I couldn't finish', etc.).

The core meaning of ように is 'in such a way'. It's used to show an action done to achieve a result, e.g. 勉強できるように新しい本を買った ('I bought a new book so I can study.'). ようにする builds on this to express making a habit or effort, like 毎日、日本語を勉強するようにしている ('I try to study / make a habit of studying Japanese every day.').

～にする・～くする and ようにする both mean making something a certain way, but differ in usage. ～にする・～くする is used with nouns and adjectives to mean ‘make into (A)’, e.g. 綺麗にする ‘make clean’ and 甘くする ‘make sweet’. ようにする is used with verbs and conveys the idea of making sure to do something, e.g. 走るようにする ‘make sure to (or make an effort to) run’.

Both can be translated in English as 'try (doing)', but differ in nuance. ようにする means to make an effort or form a habit, e.g. 毎朝走るようにしている ('I try to run every morning.') has the nuance of making a point of doing so. In contrast, てみる means to try something out to see the result, e.g. 走ってみた ('I tried running.'), which has the nuance of doing so to see what it was like.

Both ようになる and ようにする express something becoming a certain way, but differ in nuance. ようになる describes a situation becoming that way, e.g. 行けるようになった ('I became able to go.', implying external or internal factors allowed it). ようにする focuses on someone actively making it possible, e.g. 行けるようにする ('I'll make sure I can go.').

ようにする means 'to make an effort to ensure something happens a certain way' and expresses intention or habit. For example, 遅れないようにする ('I'll try not to be late.'). In contrast, ように～てほしい expresses a desire for someone else to behave a certain way. For example, 遅れないようにしてほしい ('I want you to make an effort not to be late.').

ことにする and ようにする are closely related but have different nuances. ことにする is used to express a resolution or decision, e.g. 来年、マラソンを走ることにした ('I decided to run a marathon next year.'). In contrast, ようにする expresses making an effort to carry out an action and is often used for ongoing intentions or habits, e.g. 毎朝走るようにしている ('I'm trying to run every morning.').