That LinkedIn is the #One and dominant professional networking platform is beyond doubt. But it requires a lot off diligent effort to build your network. Here are some tips, more from a personal profile point of view.
You have to be diligent. You need to earmark some fixed time to manage this activity. You need to be prompt in your response. A good way is to keep track of the notifications which LinkedIn sends you. Keep responding as they come in.
Another measure of how you are doing in building your network is the LinkedIn SSI.
It gives good insights of the profile and any number above 70 is good. To give more meaning to your SSI number it is good to compare it with another indicator - "Average SSI of people in your industry". This comparison gives more insight into your SSI number and gives good picture of where you are standing as compared to the professionals in your industry. Here it will be good to be ahead of your industry peers. If you are below, then it means you have some catching up to do. But sometimes if you are operating in multiple domains then it could be a little difficult to interpret.
The other is the "average SSI of people in your network" - here the interpretation should be exactly opposite. If you are way ahead in ranking then probably your network is not completely relevant, unless off course you are a domain authority figure.
If your SSI rank is similar to your network, then you are in a good place. If is lower then it means you need to focus more on increasing engagement, publish insightful posts and build relationships.
Finally building a network is the first step but nurturing it is more complex and time consuming.