However I really like normal pens because they looksre are various andtypes and they look artistic. However I really like normal pens because there are various types and they look artistic.

However, I (really like / prefer) normal pens because they lookshave various andstyles and are more artistic. However, I (really like / prefer) normal pens because they have various styles and are more artistic.

It sounds like you like normal pens more than erasable pens - if so, you should use "prefer"

However, I really like normal pens because they looks various diverse and artistic. However, I really like normal pens because they look diverse and artistic.

Careful using "various." Although it is an adjective, it's one of those words that isn't usually left on its own. Its more natural to have it used with a noun directly, for example: "I read various books." (correct)✅ "I read books that are various." (unnatural)❌ In this context, I think "diverse" is a better word to use :)

However, I really like normal pens because they looks various different and artistic. However, I really like normal pens because they look different and artistic.

I've often used pencil as well for oil painting, but they look the same and simple. I've often used pencil as well for oil painting, but they look the same and simple.

I've often used pencils as well for oil painting, but they look same and simplare simple and look the same. I've often used pencils as well for oil painting, but they are simple and look the same.

More natural

I've often used pencil as well for oil painting, but they look sameplain and simple. I've often used pencil as well for oil painting, but they look plain and simple.

"Same" follows a similar sort of nuance I mentioned above. I think "plain" is the word you're looking for :)

I've often used pencils as well for oil painting, but they look the same and too simplistic for my taste. I've often used pencils as well for oil painting, but they look the same and too simplistic for my taste.

Do you have a favorite stationery product? Do you have a favorite stationery product?

Erasable pens have been popular in Japan these days, and I've used them frequently at work and while studying. Erasable pens have been popular in Japan these days, and I've used them frequently at work and while studying.

Erasable pens have beenare popular in Japan these days, and I've used them frequently at work and during study. Erasable pens are popular in Japan these days, and I use them frequently at work and during study.

Alternative: Erasable pens have become popular in Japan recently,

Erasable pens have been popular in Japan these days, and I've used them frequently at work and study. Erasable pens have been popular in Japan these days, and I've used them frequently at work and study.