This guide will be something that I have found while using Cross Realm Assist, but I think any other addon with similar abilities will work as well. This probably isn't really anything groundbreaking but I decided that I will share with you (feel free to delete if this is duplicate, I have searched through some pages, but I can't think of name for it so didn't find anything :P).
First of all, this will work for only SOME achievements, items and dailies, not all of them. I have tested it on Night Elf Druid on Outland EU, I suppose it should work for anyone but you can never be sure.
So basically, this method will work for achievements similar to : Higher Learning (Higher Learning - Achievement - World of Warcraft) or Let's Do Lunch: Darnassus (Let's Do Lunch: Darnassus - Achievement - World of Warcraft), ETC, which require you to find items / complete some dailies. As all of you know those items are not always respawned, also dailies are mixed, so sometimes you might find the daily quest which is not needed for several days, therefore your achievement progress is delayed. The easier way to get around it is to use Cross Realm Assist / similar addons, to jump between realms and search the item/quest you need. In my case, I managed to get Higher Learning achievement in like 2 or 3 days, just by jumping once a day in the evening. In the same way, all achievements requiring several dailies such as Let's Do Lunch: Darnassus can be easily done in 5 days. WARNING: Most groups in cr...