A little of each can go a long way. Don't put out mass physical flyers, instead aim to post them in locations or areas (where allowed) that cater to your target audience. Some places might trade you wall space for a couple tickets.  Online,  you should factor in no less than 30 days aggressive promotion, and ideally at least 90 days. And offering any kind of presale tickets can vastly improve the money collected and encourage people to commit.