If your lvl 45 rangiong and up you've xcome to the right place, first, the number one place for you to train is with the lvl 42 moss giants a the end of the varrock sewers "maze" so to speak...before you do that, make sure you have a short bow as they are much faster than long bows and speed is necessary for this tarining. Here's a quick pic for you's thinking of following my guide.
sry about the size...
once in there, let someone attck the moss giant then start shooting it with your arrows, if not, you will be severly dmged by the moss giant as you have low defence with rnging, if someone hits it first you will be free to shoot at it and it will only attck the person who hit it first. Not only is this area a great place to get rnging exp. but it is also great for prayer seeing as each moss giant drop big bones...rememebr, that only the person who does the most damage to the moss giant will gte the big bones.
next, if you are successful in beating the giant and get the big bones, noce you bury them you may get a shade or a zombie...this area is great for these undead because there are multiple rocks you can hid behind to shoot the undead monster without them being able to hit you back (as they are melee)(this doesn't work with evil chickens as they are also long distance attckers)
make sure you are at leats lvl 45 before coming here as if you are not you will get little to none exp per monster and you will never get a drop.
also, make sure your bow is set to rapid fire (as opposed to accurate fire) this will give you more hits per monster which is what you need with everyone doing much more dmg than you
Hope this guide helps you alot