Is this OK for "How was your vacation?"

Taliller var mıydı?

Tatilin  nasıldı ?  

OR  ;

Tatilin nasıl geçti ?

Thanks. But for "Did you have a good vacation"

Tatilin çok iyi var mıydı?

Tatilin güzel miydi? 

tatil (1holiday, 2vacation)

tatil+n(possessive)---------------------->tatilin (your vacation)

http://www.turkishclass.com/turkish_lesson_259

nasıl idi

nasıl+di--------------------------------->nasıldı (how was it)

http://www.turkishclass.com/turkish_lesson_278

Tatilin nasıldı? (How was your vacation?) [direct syntax: Your vacation was how?]

Thanks. Makes sense but I can ask this with ´var´?

kedim var - I have a cat, I have got a cat

Can I say

Talilin güzel var mıydı?

No, you can´t use   "var" there.

Literally ;

* Tatilin  güzel miydi ? ---> Was your vacation good ?

If you want you use "var" with " mıydı " , we have to change it abit

Geçen sene tatilin varmıydı  --> literally : Was there any holiday of yours last year ?

  ---> Proper translation of it would be :  Did you get any vacation [from your work ] last year ?

We dont use var in that way. 

There is no such thing like having a good holiday.

Thanks. I recognize English uses ´have´ a lot.

When I was in Turkey last summer, I wanted to ask "Do you have a Blackberry?". Then I thought I missed something obvious, studying "to have". Then I found out you don´t really have a verb to have.

I hope this is correct: Blackberryin(iz) var mı?

"Blackberry" is a proper noun. Apostrophe is needed.

Blackberry´iniz var mı? (Do you have any Blackberry?)

Indeed, "sahip (owner)" can be used as well. It´s used with dative case.

Bir Blackberry´e sahip misin? (Do you have any Blackberry? (direct: Are you an owner to a Blackberry?))

But this way sounds very formal. (: