Huge space stations are not meant to be built on the ground and then launched at once. The module method works well, and you can practice docking by reading tips and dock once or twice everytime you play KSP. Also, try sticking to one simple launcher design for every payload. If you are to launch interplanetary tugs or any spacecraft that has fuel tanks in it (unless it's a refueling mission), you can construct something to drain fuel before launching or extra structures that can aid you to lift the thing to get some use for that surplus fuel. You can run refueling missions anytime after, and you can hone your docking skills in the process. As for struts, use them effectively and don't put too much every connection.