[Dark Leather Gloves], created through Leatherworking, increase lockpicking skill by 5. They reduce the chance of a lockpicking attempt failing and also can be used to pick locks slightly out of your skill range.
If a rogue is unavailable, there are several alternatives.
Locks can be opened by various Skeleton keys made by Blacksmiths. There are seven types of skeleton keys, all of which can be learned from Blacksmithing trainers. Each recipe creates two keys, which are used up on a successful pick.
There is very little consensus on what standard policies for lockpicking are; Rogue expectations can vary wildly from server to server. Some expect a tip, and some gladly open locks for free. Common assumptions can be:
If the rogue is not sending messages via Trade, General chat, or by yelling, then it is never acceptable to open a trade with a rogue without first asking them if he can open a certain box. Among other things, it can disrupt a mail composition, an Auction House scan, or a profession crafting, and can be very irritating. Many rogues will automatically ignore people who open trade windows unsolicited. However, if the rogue is clearly stating that he/she is opening lockboxes, it can be considered even more irritating to the rogue who then has to deal with floods of whispers coming in, so simply open trade.
Rogues will generally offer their service for free; it is generally expected to offer a tip if you can afford it.
If a rogue expects a fee for lockpicking, he should negotiate it ahead of time. Otherwise, gracious players often tip anywhere between 2 and 5 to the opening rogue, based on the type of lockbox opened. Locks under Thorium Lockboxes usually are tipped 50 and Thorium and above are tipped 1 on most servers. A generally good guideline to follow would be one silver for every skill on the lockbox (ex. Thorium Lockboxes would be 2 50.
If you ask a rogue before opening, he/she will often open it for free.
Always ask friends and guild mates before asking strangers. You are more likely to get it opened and more likely to get it done for free or a discounted price.