Thunderfoot
Hero
I once started a campaign where all the players began as solo adventures "side quests" that brought them to a certain location. From there, it was a matter of the players futzing around until they found each other. It was actually very effective in creating a "group" feel because they had to learn about each other rather than trying to show horn a reason for their mutual existence.
I do tend to follow the old school method of campaigning that when the party reaches town, some things are going to take more time than others, so if the mage needs do research or the priest or pally has to do a quest, the others are free to go it alone. Again, this ends up being solo adventures so that the whole party isn't sitting around while one player is getting all the attention. Though on occasion I have allowed the party members to cross paths during their solos with some interesting results. (I had a thief (2ed) who went to pull a heist, meanwhile the fighter decided to take a temp job in the town guard. The fighter actually arrested the thief leading to that character's death on the gallows, at the hands of another PC who took a temp as an executioner. And it was all completely by accident.)
During the campaign I try to allow the storyline to take individual characters to the spotlight for "legs" of the journey but try to give even the "side" adventures a sense of party identity. For instance if a fighter needs to go to a location to avenge his little brother's death at the hands of an evil overlord, I try to also have either parallel plots that keep the party moving in a similar direction or give the overlord traits that tick off the other player's so they are more invested. (i.e. rival gods, ethics, political focus, etc. I even had a mage go along with a revenge scheme once simply to get at the rumored library the BBEG had (and it WAS a rumor))
I do tend to follow the old school method of campaigning that when the party reaches town, some things are going to take more time than others, so if the mage needs do research or the priest or pally has to do a quest, the others are free to go it alone. Again, this ends up being solo adventures so that the whole party isn't sitting around while one player is getting all the attention. Though on occasion I have allowed the party members to cross paths during their solos with some interesting results. (I had a thief (2ed) who went to pull a heist, meanwhile the fighter decided to take a temp job in the town guard. The fighter actually arrested the thief leading to that character's death on the gallows, at the hands of another PC who took a temp as an executioner. And it was all completely by accident.)
During the campaign I try to allow the storyline to take individual characters to the spotlight for "legs" of the journey but try to give even the "side" adventures a sense of party identity. For instance if a fighter needs to go to a location to avenge his little brother's death at the hands of an evil overlord, I try to also have either parallel plots that keep the party moving in a similar direction or give the overlord traits that tick off the other player's so they are more invested. (i.e. rival gods, ethics, political focus, etc. I even had a mage go along with a revenge scheme once simply to get at the rumored library the BBEG had (and it WAS a rumor))