At the moment nothing really. For grass grows rapidly this time of year and grass being like 99% of all other plants it grows upward instead of sideways in its natural state.

You could search for a Lawn Mower Striping Kit to fit your mower if one is available. I have saw people use everything from 2"x? boards to PVC pipe attached to the rear of mowers in an attempt to get a striped lawn.

I am into stryping. I live in Maryland I know nothing about Bermuda Grass.
I do know this. For stryping the reel mower with the front roller does one of the best jobs for the Homeowner.
There is a lot of weight on the roller and it does bend the grass. Even though it bends the grass it does cut what bows back.
As for the stryping kits that trail behind the push mowers they are a royal pain and eventhough they are filled with sand they do not perform better than the front wheel on the Mclane.
I am using a Hayter 56 22 in stryping machine. It does a excellent job on tall fescue. The only problem is that it cuts only 2.5 inches and not 3.
The taller the grass is the easier it is to show the stripe.
I see Honda sells stryping lawnmowers in the UK.

I'm also a HUGE fan of the reel roller. I've had one on a 20" McLane for 5 years and then upgraded to a 27" Tru Cut. Both mowers had the front wheels for about 2 weeks and then I had to install a roller. The wheels don't keep the mower level and I end up scalping around flower beds and my sidewalks. The stripes are just a bonus to me, I can't stand spending money on a great lawn just to scalp it every 3 days. Here's a few pics.