Here is a short guide on how to get an experienced lobby going.
as a prerequisite you need to following:
A large amount of high level players on your friends list
Clan leaders and other prominent officers, ca's, active players etc. on your steam friends list.
The ability to be the friendly host.
How to get players on your ingame friendslist?
Add every player that you enjoy playing with to your friendslist.
Add every active experienced players to your friendslist.
Add Clan leader and their members to your friendslist.
How to get players on your steamfriendslist?
You: "Hey can I add your to steam for future game purposes?"
other guy: "Yea just add me, feel free to invite any time."
simple as that.
Why do you have to be friendly?
When you invite players to your lobby, they are joining because they want to play with you and other experienced players. If you are a grumpy player with a tendency to behave in a not so friendly manner other players wont join your lobbies.
Now to the good part:
How to set up the lobby, and how to get people to join.
First go to custom game, setup your lobby.
look through your ingame friendslist and invite everyone not currently ingame.
-some will say they cant, or will join later. That doesnt matter just get people in.
now a few have joined, maybe 5-7 players but you are missing the rest.
tell the people in your lobby to go through their friendslist and steam list and invite players.
now go on steam friends yourself and look for clan leaders and your friends. Invite them.
Some will join, if you are still missing people ask the clan leaders to invite their members.
at this point you might be missing 2-3 players, click on open up to queue and let 2-3 players join through MM.
It works.
Remember people joined to play with you and other experienced players, if you dont behave or do an effort to balance it out, they get bored and leave. It takes effort to get good lobbies going, always have always will