One of the very first things i did with my Triban 5 was to replace the awful bar tape! (i also did this on the b'twin Triban 3 i bought, but that's another story) Although Decathlon have produced a well spec'd road bike, considering the sub £500 price, it amazes me that they couldn't spend slighty more on little details like tape.
I've replaced the bar tape with a Cinelli Gel Cork bartape in white. I think it complements the overall look quite well.
The comfort benefit makes it a very worthwhile, and cheap modification. I'd recommend you try it! I got my Cinelli bar tape from amazon for around £10.
Here's a view from the riders perspective:
As you can see, i'm a bit of a bike gadget freak... but more on that later.
I'm no expert on wrapping handlebars, so i don't have any big tips other than wind the tape tightly, don't let it go slack and never let it go or it will unravel instantly! Most bar tape comes with a short amount of finishing sticky tape to hold everything in place, but you'll find it doesn't do a good job. I find it's best to have some electrical tape on hand instead.
Check out some of the videos on youtube to see how its done. Be brave, it's really not that difficult.