ようになる and ようにする: change and effort
Becoming able to do something differs from consciously trying to do it. Read the choice of なる or する together with the preceding verb.
Describing a change from before
漢字が少し読めるようになりました。 says that one has become able to read some kanji. The ability expressed by 読める has changed from before. This is more than a promise to try to learn to read.
毎朝歩くようになりました。 can describe a new habit of walking every morning. A potential form is not required in every use. Compare what happened before with what happens now.
Making a conscious effort
約束の時間に遅れないようにします。 expresses an intention to avoid being late for appointments. It presents a conscious effort toward 遅れない, not a report that the speaker already never arrives late.
毎日、日本語を声に出して読むようにしています。 describes making a regular effort to read Japanese aloud every day. ようにしている can express an ongoing practice without guaranteeing flawless adherence.
Checking results separately from plans
泳げるようになった reports becoming able to swim; 泳ぐようにしている describes making swimming a regular practice. The difference between 泳げる and 泳ぐ matters alongside the choice of なる or する.
When recording progress, separate what you can now do from habits you intend to maintain. Otherwise, a study plan can sound like an ability already achieved. At the next review, check whether each statement is still accurate.
Check: Do 読めるようになりました。 and 読むようにしています。 mean the same thing?
Show the answer and why
No. The first reports becoming able to read; the second describes making a conscious practice of reading. Distinguish an achieved ability from effort in a routine.