Always wear a helmet!

It is important to maintain the proper level of hydration when bicycling. During a multi-day bicycle tours, it is easy to become partially dehydrated. If that happens, you will have less power, will be less efficient and are more likely to get sick or have heat related problems.
Drink before the ride(starting the day with juice or water with breakfast), Make sure you drink enough during the ride(1 bottle per hour at a minimum) and drink after the ride! Tap water is drinkable in Croatia.
Make sure you always have enough water before your ride. Carry food and a couple of water bottles so that you can eat and drink at regular intervals.

Keep your tires inflated to the limit indicated on the side of the tire. An under-inflated tire requires more effort to turn and is more prone to blowouts.

If riding in group, ride in single file avoid pulling too hard on the front brake lever. Brake smoothly! Hard braking is a common cause of cycling injuries. This can cause the brakes to lock and the rider to fall over the handlebars.

When cycling past parked cars try to give them a buffer of at least one meter (three feet) in case a door is suddenly opened, otherwise you may take the door prize.

Don’t forget sunscreens!

Don’t wear headphones. You need to hear what’s going on around you.
Flag your intention to turn by hand signaling. Ride in a predictable way, about one meter out from parked cars.

Always wear brightly colored clothing. It is harder for motorists to see you if you are dressed in dark or dull colors.
Fluorescent fabrics markedly increase your visibility to other road users.

When in doubt, walk. Biking can really be dangerous. If a hill looks too steep or a curve too tricky, get off.