The Independent Office of Police Conduct (IOPC) made these recommendations after investigating how police handled calls for help from Shana Grice, who was being harassed by her ex-partner.
Days after her last complaint, Ms Grice was found dead in her Brighton home.
Lane had slit her throat and tried to burn her body.
As part of its final published report on the investigation, the IOPC detailed how Sussex Police responded to Ms Grice before Lane murdered her on August 25, 2016, and issued recommendations to police chiefs across England and Wales.
IOPC Regional Director Sarah Green said: “We have been in regular contact with Sussex Police during our investigation and since its conclusion, highlighting potential issues with how the force was handling allegations of stalking and harassment.
“HMICFRS also conducted an in-depth assessment of the force’s performance on stalking and harassment and has raised concerns.
“It is vitally important that as part of our work, good practice is recognised and shared, while shortcomings, be it in policies, systems or training, are identified and improved.
“Sussex Police responded positively to our informal recommendations but the HMICFRS report published in April shows there is still work to be done. The formalising of our recommendations is another step towards ensuring improvements are made.”
In a series of tweets, the IOPC also said: "Improving how domestic abuse and harassment are policed is one of the IOPC's key areas.
"As part of this we launched a national campaign to raise awareness of silent solution."
As well as issuing national guidelines to all police forces, the IOPC made a raft of recommendations to Sussex Police – telling it to properly train staff, improve risk assessments, communicate better and use systems correctly.
The College of Policing and National Police Chiefs Council have also been told ensure officers and staff have the skills to do their jobs properly when investigating crime.