You can look for a party at anytime. You can look for members for 60 mins. at a time. go to menu>party>search (make sure the job you want to party with is selected)>search. Anyone who is looking for members in your level range automatically comes up. Usually there will be some sort of comment so, check it before joining. I know this takes some actual work on your part instead of getting a random tell while farming but, it works.
I have to agree the current party system is excellent apart from one thing, 90% of the players don't use it.
When I want to setup a party I go into it start a recruit and set exactly what jobs and ranks I am after, along with a comment about what we will be doing in the party and where it will be, then I can carry on with whatever I am doing. Then anyone who wants to party clicks on party search and if they fit the criteria I am looking for my party will show up in the list. Then they can read my comment on what and where we will be going and if they like this they can jump straight into the party from anywhere in the world. Then when we are out grinding and someone leaves I can put a recruit back up for the class and rank I want. No need to search through a list of people LFG sending tells and waiting for replies, it's easy and I can go back to grinding and someone who fits the criteria will join.
I can even use it to look for a crafter of a certain rank or higher to make me something and all sorts of other things, but there is one huge problem. The problem like I said before is no one uses it and instead of learning they just want to put a flag up and wait for someone to send them a tell. Well as a party leader I would rather spend my time grinding than look for a replacement for the person who dropped at short notice or spend that time crafting or doing something instead of sending tell's to everyone and waiting for replies from people who are AFK.
With the party search you don't even have to be on your current class to find a party if you want to use your CON but your on MRD at the time then you just set your search for CON and any parties looking for a CON in your level range will come up.
I really wish people would start using the system as it is actually pretty good if you give it a chance.