Its also best to reload every webpage as with todays standards they update them on the fly i.e. Everyday. With internet speeds at the the momement a few seconds isnt going to hurt you.. Enable the clear of cache (delete everything) when you close your browser.. Which will clear everything and so when you come to use the website again then it will load up everything from the webstite and not use the cache.. I now some people love the cache and speedy load times but seriously to solve everyday problems use the Clear of Cache at close.. Remember these options are configurable and remember to unclick cookies if you like to keep signed into facebook etc..
But i use it all the time.. Obvioulsy keep cookies etc but Clearing the cache is a must if you want error free browsing.
*NOTE this is an idea.. You do not have to do this.. Also you will need to read your browsers help to turn on this function*... *also im not responsible for your loss of logged in websites if you have cleared the cache without unclicking cookies then its your fault not mine*** Now that boring bit is out the way.. If you want me to explain for each browser let me now..