Careful consideration is needed before making a decision.
To think things through.
"Careful consideration is needed before making a decision" -
'carefully' means to do something intentionally that will avoid harm or error.
'consideration' means to think about something, typically after a long period of time.
In this regard, to carefully consider something means to think about your decision for a long time, analysing the outcome and intentionally avoiding harmful consequences or making mistakes.
"To think things through" means thinking about a situation and all the possible outcomes or consequences before making a decision so as not to make a mistake.
例文
"Careful consideration is needed before making a decision" -
決断する前に慎重に考えることが必要です。
'carefully' は損失や間違いを避けるように何かを意図的に行うことです。
'consideration'は通常物事を長時間考えることです。
この点では、to carefully consider something（物事を慎重に考えること）は、物事を決断するのに長時間考えて、結果を分析し、有害な結果や間違いを犯すことを意図的に避けることです。
"To think things through"（物事をよく考える）は、間違いをしないように決断する前に、あらゆる起こりうる結果について考えることです。
Well, when you make a decision, it can be a 'hasty decision' which implies insufficent thought, or it may be a 'careful' decision which means it was safe - possibly conservative and unlikely to affect anyone badly. An 'informed decision' means that you have assessed all available information, especially perhaps some previously unavailable information.
To chew something over = discuss or consider something at length, meditate on, ruminate on, think about, think over, think through, mull over, contemplate, consider, weigh up, ponder on, deliberate on, reflect on, muse on, cogitate about, dwell on, take stock of, give thought to, turn over in one's mind, consider the pros and cons of.
"Executives met to chew over the company's future."
何かを決める時、十分に考えずに早まった決定になりがちです。又はおそらく保守的で誰にも悪影響を及ぼさないような安全で慎重な判断になるかもしれません。
'informed decision'（十分に情報を得た上での決定は） は、特に以前は利用できなかった情報も含めて全ての利用可能な情報を評価することです。
To chew something over = （長時間考える、熟考する、よく考える、賛否両論を考える）
例文
"Executives met to chew over the company's future."
重役は会社の将来をよく考えるために集まった。
There are several words you could use,
"Review"
"Consider"
"Think about"
"Reflect on"
Here are some ways you can use these words.
"We need to review this paperwork before we sign any agreements."
"Tom will consider his next move before he gives William his final answer."
"We need to think about this proposal."
"I will spend time reflecting on what you said about the vehicle before I offer to buy it."
Each of these words gives the idea that you will think about something carefully before making a decision!
Hope these help!
思慮分別の意味で使うことができる言葉はいくつかあります；
"Review" （再吟味する）
"Consider" （熟考する）
"Think about"（～について考える）
"Reflect on" （顧みる）
これらの単語を使った例文は以下の通りです：
"We need to review this paperwork before we sign any agreements."
（契約書にサインする前に、この書類を見直す必要があります）
"Tom will consider his next move before he gives William his final answer."
（トムはウィリアムに最終結論を出す前に、次の動きを検討するだろう）
"We need to think about this proposal."
（この提案について考える必要がある）
"I will spend time reflecting on what you said about the vehicle before I offer to buy it."
（私はその車を買う前に、車についてあなたが言ったことをよく考えてみます）
これらの言葉はそれぞれ、決定する前にそれについて慎重に考えることを示しています！
お役に立てれば幸いです！
Explanation:
'The pros and cons' are like the upsides and the downsides. By weighing out the pros and cons you are carefully considering everything before making a decision, so you make a wise decision.
'Carefully considering everything' or 'taking everything into consideration' are one and the same and mean that you are looking at something from all angles prior to making a decision.
説明：
'The pros and cons'は、良い点を悪い点ということです。
長所と短所を計りにかけ、慎重に検討してから決定することで、賢明な決断となるでしょう。
'Carefully considering everything' と
'taking everything into consideration' は同じ意味で、
意思決定を行う前にあらゆる角度から見てみるということです。
If you have an important decision to make then you might have to think about it for a while we have a term for this 'to think long and hard' which can also be called 'careful consideration' meaning youare really thinking what to do for the best
重要な決断を下す前には、長い時間考えなければならないかもしれません。'to think long and hard'（じっくり考える）はこれについて表す言い方です。他に 'careful consideration' と表すこともできます。'careful consideration' は「熟慮」という意味です。
To 'mull something over' is to think about the thing a lot. So if someone asked you a very difficult question, you could say "I need some time to mull it over". Or if you have thought long and hard about a decision you could say "I have mulled over this decision and ...".
mull something over' は「～についてよく考える」という意味です。ですから、例えばすごく難しい質問をされたときには、
"I need some time to mull it over"（考える時間が欲しいです）
と言えます。
もしある決断についてよく考えたなら、次のように言えます。
"I have mulled over this decision and ..."（この判断についてはよく考えました ...）
アメリカ合衆国 
南アフリカ 
イギリス 
ニュージーランド 
