Guys how are you cold emailing or talking to recruiters on linkedin

I've been trying to switch since a long time and no one is replying...2 recruiters reached out , but they didn't respond back after receiving my resume...I don't think they even saw it.i need your help with understanding

1. How to initiate convos with HRs/Recruiters without getting ghosted
2. How to look to apply for jobs in this market? Any tips and tricks.?