what's better than a milk crate? lol

Google is your best friend for such matters as DIY.

I Google'd DIY speaker stands and got plenty of info including step by step instructions and materials list.

Arranging them to the height you prefer using them at ought to be decided upon first, then proceed accordingly.

The aspect or inquisition of or on, "What's the best... XYZ?", is an effort in futility.

This hobby, like any other, is so prone to user identification and disidentification, the ONLY answer to the querry of 'what's best' will be utterly determined by YOURSELF.

In any area, with any device, and in any arrangment....

Fortunately today, there's absolutely tons of good to very very good, stuff around, regardless the application. Many DIY projects were or are replicas, or reverse engineered clones of current well performing items. other DIYs are based on the same techniques as one will find in the 'ready rolled' high dollar originals.

it's more the approach for your application that i feel is the path you should ascribe to, than anything else... ie., coupling or de-coupling, those squeakers of yours. Both aspirations can be done with the same stand (s)... if you make 'em or buy 'em.

One thing I've found about stands and racks... the harder the materials being used, the more critical is the technique for damping them. heft... mass... sheer weight.. and damping are the factors which make a good support.... usually.

My Phase Tech PC 6.5 two ways use a 10-12 inch stand with a slight tilt. All rubber mounts... no spikes. I use them as fronts in my BR HT system. sitting or Laying on the bed my ears are certainly above the tweeters.

there is indeed a tonal shift when the ears are at, above, or below the tweeters... BUT as this hobby is user defined, to each their own.... and why I said play with the height first to see what is prefered.