Don't let anybody tell you that LinkedIn messages are waste. Considering that you have the right pitch for the right product (you sell) and person (you are connected with), LinkedIn messages work!
Below trick to get leads is simple and effective.
Create a post that targets specific group. You need an effective post (not necessarily funcy) that attracts your intended audience.
Place the post on your LibkedIn page
Boost post for 30 days by associating the right-fir audience
Check out you likes on you post and connect with the users
Send them a message (upon accepting your invitation) leveraging on their 'like' to you post
Start a conversation usins -preferably- sales navigator
You can have around 100 new leads every month that are ready and intrigued to listen from you about your products
Create a product group and invite them to establish loyalty and continuance