考えます translates to English better as 'to think about' or 'to ponder' So, you normally don't say, "I want to go to that restaurant, I ponder/think about." You say, あのレストランへ行きたいと思います Which is "I want to go that restaurant, I think." Another example is when someone asks you out like so: 出かけましょうか？ わからない 考えてね Let's go out? I don't know Think about it, alright?

思う means "feel" or "judge", and the trigger from outside. This is soft word and good in speaking Japanese. I think 思う is the most popular word aroud the mean of "think". When you can't judge which is better, 思う is always natural and better than 考える. 考える　judge, expect or consider (from the past memory or information you already have). This is more powerful action than 思う. Inside your head, the brain works hard, and calculate, it's 考える. "I think you should think about your future more seriously! " あなたは自分の将来についてもっと真剣に考えるべきだと思う！

I think ~. 私は～と思います。 私は～と考えます。 Both are correct. But we generally use 思います. Maybe 考えます is used than 思います when we express logical. But I have never seen a person who says 私は～と考えます. And We use 思います when we want to tell someone our own opinions or ideas. e.g. 私は彼が正しいと思います。 I think he is right. 考えます means using our own heads. e.g. 私は将来について考える必要がある。 I need to think about my future. Can you understand? My English is not good and Your question is a little difficult to explain in English. hahaha

About [I am thinking of you], you can see the next good explanation on http://chigai-allguide.com/%E6%80%9D%E3%81%86%E3%81%A8%E8%80%83%E3%81%88%E3%82%8B/ . 「相手のことを思う」と言った時は、相手を恋しく思ったり、心配したりする感情を表し、「相手のことを考える」は、より分析的で、その状況などについて思いめぐらすことを表す。 __________________________________________________________ My translation is below. When we say 相手のことを思う, it expresses the feeling to miss the partner or to worry about the partner. And when we say 相手のことを考える, it is more analytic and expresses to ponder/think over/recollect about the situation and so on.

In my opinion, 考えます and 思います are different. 考えます means I guess about something. 思います means I think about something. Besides, in Japan we use 考えます when we create our opinion with thoughts or experiences or facts...etc. In contrast, we use 思います for just feeling or first impression. Overall, the differences are how many time we use about it. 考えます is we use longer time than 思います。 Sorry my English is rubbish but I hope this answer will help you.