ALSO POSSIBLE: Summer is ComApproaching ALSO POSSIBLE: Summer is Approaching

When I worked out this morning, I sweated a lot, and it felt like a summer morning. When I worked out this morning, I sweated a lot, and it felt like a summer morning.

I would include the word "real" in the last clause: "it felt like a real summer morning." I think it is optional but it feels more natural to me to add it.

When I worked out this morning, I was sweateding a lot, and it felt like a summer morning. When I worked out this morning, I was sweating a lot, and it felt like a summer morning.

When I worked out this morning,(,) I sweated a lot, (,) and it felt like a summer morning. When I worked out this morning(,) I sweated a lot (,) and it felt like a summer morning.

NOTE: The commas are optional. You can safely delete them.

I shared this with one of my friends, who has the same morning practice routine as mine. I shared this with one of my friends, who has the same morning practice routine as me.

I shared this with one of my friends, who has the same morning practice routine as mine. I shared this with one of my friends who has the same morning practice routine as me.

"as me" sounds more natural here

I shared this with one of my friends, who has the same morning practice routine (or "exercise routine") as mine. I shared this with one of my friends, who has the same morning practice routine (or "exercise routine") as mine.

I shared this with one of my friends, who has the same morning practice routine as me/mine. I shared this with one of my friends, who has the same morning practice routine as me/mine.

I shared this with one of my friends, who has the same morning practice routine as mine. I shared this with one of my friends, who has the same morning practice routine as me.

If you want to use "mine," it would be "whose morning practice routine is the same as mine"

She told me the heat woke her up because she was still useding a thick quilt. She told me the heat woke her up because she was still using a thick quilt.

"woke her" (without "up") works on it's own, but we usually say "woke her up". Changed the tense from "still used" to "was still using".

She told me the heat woke her up because she was still useding a thick quilt. She told me the heat woke her up because she was still using a thick quilt.

She told me the heat woke her up (or "woke her from her sleep") because she still usedslept with a thick quilt. She told me the heat woke her up (or "woke her from her sleep") because she still slept with a thick quilt.

She told me the heat woke her up because she was still useding a thick quilt. She told me the heat woke her up because she was still using a thick quilt.

She told me the heat woke her because she still used a thick quilt. She told me the heat woke her because she used a thick quilt.

Still isn't necessary

Each season is lovely, but it'now is the time when I need to wear my hat and sunglasses every time I go out. Each season is lovely, but now is the time when I need to wear my hat and sunglasses every time I go out.

Each season is lovely, but it's become the time when I need to wear my hat and sunglasses every time I go out. Each season is lovely, but it's become the time when I need to wear my hat and sunglasses every time I go out.

Each season is lovely, but it'summer is the time when I need to wear my hat and sunglasses every time I go out. Each season is lovely, but summer is the time when I need to wear my hat and sunglasses every time I go out.

Each season is lovely, but it'this is the time when I need to wear my hat and sunglasses every time I go out. Each season is lovely, but this is the time I need to wear my hat and sunglasses every time I go out.

"This" makes it more clear that you're talking about summertime I don't think "when" is needed

It's a bit frustrating that mMy hat always messes up my hair, which is a bit frustrating. My hat always messes up my hair, which is a bit frustrating.