It depends. If somebody was previously someone you used to always think of, it is "were". If you still always think of them, use "are"
"You are always on my mind." This means he/she is still on your mind.
"You were always on my mind." This means he/she is not on your mind any more.
You always use 100% of your mind (brain). There is an old wives' tale that says we only use 10% but that isn't true.
always use your mind with patience.
Always on My Mind was created on 1987-11-30.
"They are always on my mind."
Always on My Mind - album - was created in 1982-02.
Always on My Mind - 2014 was released on: USA: 2014
She didn't always have a positive mind set.
You don't. That's not an idiom. You are probably thinking of the phrase bear in mind, which is not an idiom. "Bear" means to hold or carry something, so "bear in mind" just means to keep something in your mind or think about it.Bear in mind, you should always look up the meanings of words in a dictionary.
Brenda Lee made the first recording of "You Were Always On My Mind".
You were always gentle on my mind. A gentle nudge kept the child safely on the merry-go-round.
Bob was always passionate about what he did; he would work relentlessly if he set his mind to something.
There is not a way to be in a girls mind. The only person that can be someone's mind is that person.