Seasonal hiring: what is paying well this year? - what worked for you?

I am looking at seasonal jobs around Cincinnati that might lead to something longer. I am in Cincinnati, in case local advice matters. I would like to avoid a gap in my résumé. Is it worth applying to several at once?

Thanks for writing this out. I went through something close to it 13 months ago, and it got easier once I kept a simple log of every call and form.