After trying all sorts of Bus Bars (low and medium cost) these are the most efficient. Best prices for these can be found at All Electronics when available (I don't see any now.).
Barrier Terminal Blocks above can be purchased with 2 to 16 positions. Use blocks with screws that hold down a binding head.
See on this page Toy Train Layout Wiring - Wire Management
These Terminal Strips are on one of my Control Carts shown here: Toy Train Layout Wiring - Bus Wiring