If UEFA & FIFA are serious about eradicating racism in the modern game then their message has to strike two themes with each punishment: a Financial Penalty intertwined with Community Outreach
For example, don't make teams play in an empty stadium. Instead make the club give away 10,000 free tickets to local schools & charities while providing free concessions. Then use half time to present a short video or event dealing with the negative effects of racism. Furthermore, if this continues then use the same tactic above but increase the free tickets by increments of 5,000 until you reach 25,000 or capacity as this would represent three further incidents of misconduct.
If the club still continues to experience issues with racism during continental tournaments then hold their "home" matches at neutral sites selected by UEFA under the same free ticket premise. These neutral sites must remain within the nation of the "home" club & hold crowds large enough to maintain the increasing 5,000 free tickets counter. However, if the issue is domestic in nature then I'd suggest making the team play in their countries neutral national stadium (ex Wembley).
Although clubs will love the "good will" associated with their clubs during these events. The costs will surely be larger than the fines currently levied and teams will be forced to do some policing of their own. Hopefully, this also generates a discourse that can lead to some real change.
As for Lazio (or any other team at the initial level of being "fined" for racism) all fans wearing the jersey or scarf of the opposing team gets free parking and/or a particular concession like popcorn or small soda at the corresponding fixture. I assure you that Lazio doesn't want an internationally broadcasted home game in Italy to look like a Spurs family reunion.
What do you think?