1. First, you must decide with absolute certainty that you wish to undertake your quest. Qualms may result in death.
2. Dress for the occasion. Perhaps a sturdy wardrobe made of flame retardant material would be the best choice (you may think this is obvious, but heroes are not always the most logical breed).
3. Select a weapon. This step is very important. If you choose a weapon that is too heavy, you may find it difficult to run away from projectile flames. However, you will need a durable weapon that is more than capable of defeating a dragon. A sword is heroic, but a crossbow is practical.
4. Begin journeying toward your destination. Bring plenty of food and water, especially if you are venturing into unfamiliar territory. Spending time scavenging for nourishment is a waste of time, resources, and energy. *Note: non-aromatic foods are best. Though less delicious, they will attract fewer unwelcome guests.
5. There are many permutations of the various steps that will occur from the time you set out to the time you reach the dragon. These are too many to list in full and not necessarily interesting. I will provide only a few as an example.
6. First: If you happen to be taken prisoner by ogres somewhere along your journey (this is most likely if you are travelling through a forest), it is best to try to trick them with some sort of riddle or puzzle rather than attempt to run away. This is because ogres are quite stupid, but deceptively fast runners.
7. Second: If you find that you have to cross a stream or river during your journey, first, try to locate a bridge. If there is a bridge, send a disposable member of your party to test its strength. Depending on the result of this test, either follow this member or find some other way to cross. In the latter case, you may fashion some sort of raft and cross at a narrow point in the river (though before you waste your time, check the depth of the water as you may be able to simply wade across).
8. Third: If you encounter a rival hero on a quest of their own, feign friendship and hope they leave you alone. If you find you are unable to feign friendship, make sure your party is larger and has better weapons before engaging in combat.
9. There are many other possible obstacles that can occur on your journey, but I can't be expected to do all the work for you. Are you the hero of this story or not?
10. Now that you have reached the dragon's lair (most likely a cave high in the mountains, though it could potentially live near a tower inhabited by a princess), prepare to fight.
11. The element of surprise is your best weapon, so don't squander it by striking too early. Bide your time and wait until the dragon is not on its guard. However, do not wait until it is asleep. Dragons are most dangerous when they have been awoken from a deep sleep and are more likely to strike at random. This makes them unpredictable in which case I cannot help you.
12. Decide if your party will accompany you or if you will attempt your quest alone.
13. Creep toward the dragon, hiding behind rocks as best you can. Get as close as you can without drawing its attention.
14. At the right moment (you will have to judge the right moment for yourself as there is no formula to determine the this), emerge from hiding with your weapon raised.
15. If you have chosen the crossbow, aim and shoot between the eyes. If you chose to be recklessly noble and have only a sword, run toward the dragon with an unnecessary yell of fury and stab along its tail and feet, as that will be all you can reach with a sword.
16. If you chose the crossbow, raise your arms in victory, for you have slain the dragon (unless you are a poor shot, in which case it would have been better to stay home).
17. If you chose the sword, continue randomly swinging and stabbing and hope to get a lucky opportunity.
18. If you have survived, return home in victory with your party (unless they accompanied you in the fight, in which case they are most likely all dead; additional survivors are superfluous on quests of this sort) or with the recently rescued princess (who doesn't necessarily want to marry you as you are a stranger).
19. Tell tales about your travels, with as many embellishments as you wish, for the rest of your days. These stories will most likely earn you many free pints in various brew houses.
20. Die of old age, leaving behind a legacy of bravery that future generations will both doubt to be true and wish to surmount with deeds of their own. Placing unrealistic expectations on your descendants is a sign of a true legacy.