There are two paths that lead to Bottle Beach, one goes through the jungle, the other more or less along the water. We have both tried for you. You should be on both ways with shoes on the way and take enough water. Since a mobile network is not available on a good part of the route, you should not set off alone on your way. This may sound a bit more tragic than it is, but nobody is immune to ankle.
The path through the Jungle is the shorter and less dangerous, while that at the coast along really some pretty challenging passages ready. It is recommended to go in the morning, when the sun is not burning down. The Way back can you be comfortable with the taxi boat if you want to run but please note that it gets dark here early and fast. Once dusk has set in, you no longer see where you put your foot in the jungle!
Both trails start at Haad Khom (Coral Bay). You drive up until you come to a stop sign, there you have enough space for parking. On foot you pass the stop sign and then you see the entrance to the right hand jungle trail, this is also marked by a signpost. 
As a guide yellow-blue markings appropriate, but the way is basically well recognizable. There is a place that could mislead you, so we will show it below in pictures.
You step out of the thicket and see this mountain panorama.
Look to the left, there is your further way marker.
On this trail you are, as an average, about one and a half hours pure walking time on the way. It is an unpaved dirt path right through the jungle. It is a long and steady uphill climb, often boulders, tree trunks and roots have to be overcome. In some places the jungle thins out and offers wonderful views of the sea. Shortly before you reach Bottle Beach, you catch a fantastic view of the bay - the anticipation increases. 
The coastal starts very inconspicuously. You follow the sand road after the entrance to the jungle path still a piece. If you walked straight ahead, you would come to a rocky bay next to Haad Khom, the trail will take you across a clearing of scrub with your right hand. The entire trail is with the famous bottles marked, look for them. This route offers wonderful views of the sea. Unexpectedly, in the middle of nowhere, you also come across remnants of buildings. About halfway you come to a large rock plateau that really invites you to take a break. For the entire route you have to walk with an average walking time of two and a half hour expected. 
The coastal trail is not easy, honestly! Here are solid shoes a must, in addition, you should generally not be afraid. There are sections where you almost climb a mountain goat over rocks, or circling it on narrow, slippery edges. Often you have to walk downhill over scree and push yourself through the thicket. Also pay attention to cavities between boulders superficially covered with earth and leaves! This route requires in places the use of all four limbs, plus the hindquarters.
Anyone who is reasonably fit and does not just go hiking on vacation will definitely be able to cope with both routes. If you are not sure or do not have much to do with hiking you should choose the jungle path. Both ways are beautiful in their own way and have a lot to offer. On the coastal path, surefootedness is an indispensable prerequisite! With children we would recommend the way through the jungle, however, they are used to hiking and trekking tours speaks nothing against the way along the coast.
Also interesting:
Beachguide: Bottle Beach (Haad Khuad)
