if you have straight thick hair naturally then you will not be able to get a curly look without tongs or a heated appliance.

more than likely both ash and preity scrunch dried their hair or it just needed light styling with a diffuser as they both have naturally wavy hair

your hair will prbably require more work and definite curl formation using an appliance

Hey Princessv,
I dont know what Preity's hair looks like in DCH (havent watched it). But I've seen Dhoom2.
Here's the way I go about creating soft wavy hair/soft curls (depends on how tight you want the curls).
You will need heat protector (a spray or creme formula). I like Kerastase ciment thermique and L'oreal tec is good for dryer hair. You also need hair straighteners (very versatile as they also curl hair). Some bobby pins and hair spray. The straighteners should not be too wide. GHD ones are ideal but any which have about 1-2 inch barrel width are fine!

First of all, believe it or not, the curls will turn out better in 'dirty' hair. That is to say, dont wash it on the day you want to create this look. Somehow, the grease in unwashed hair keeps the curls held together better. Nevertheless, if you have washed your hair, just blowdry it straight to start.
Begin with dry hair. It is very important to protect your hair so use some heat protector and apply to your hair. Then, starting from the back and by pinning aside the rest of the hair, take small sections of hair. Section hair using clips or pins. The section depends on how wavy/curly you want the look. I would take about 5-8 cm sections for Ash's look.
Take your straightening irons and wind the hair around them (from the roots going down to the ends). Make sure you dont go too close to the scalp. Start an nch away from the scalp and wind around the barrel of the straightener and pull down. The total 'hold' time should be about 5 seconds. This gives the same kind of effect as pulling scissor edges along ribbon to make it curly.
As you wind the hair, pull the straightener down so you dont apply the heat for too long and singe your hair. Again, the tightness of the curls will depend on how you wind the hair and how long you apply the straightener for.
Continue to work with sections of hair as such going from the back towards the fron of your head. When you come to the crown and fringe, decide what side you want to part your hair and curl your hair accordingly.
You say you have thick hair so you'll need lots of patience with getting all the hair done. My arm usually hurts after 15 mins lol. You might want a friend to help you out (especially with the back of the hair).
The good thing is that OTT perfect curls will actually look fake so dont worry too much about as long as you're curling your hair. Messy curls will look good.
Finish off with hairspray to hold the look. You will find that the curls will 'fall' as the day progresses. Dont use a very strong hairspray or your hair wont have natural movement. Use one with just enough hold to keep the look together but allow flexible movements. My personal recommendation is L'oreal Invisible studio fix.
A cute bobby pin with diamante can be used on your fringe and is a great way to accessorize.
There are other ways to curl your hair eg using hot rollers etc but this one I find is the easiest and most effective/do-able.
All the best and lemme know how you go.