Well first of all you need to grow the right type!
The next thing is variety , some varieties are better than others!
The top growers usually grow from selected seed or pips.
There are many methods to blanching and the best usually entail mechanically excluding light from the stem above ground rather than covering below the ground.
Some people use pipes, others use pipe insulation or bituminous paper.
So any means of covering the stem is paramount.
Then there are the leaves these should not be allowed to break as this reduces the flow of chlorophyll and beneficial nutrients.
Top growers drape the leaves on horizontal wire/ cord to ensure they don't crease and keep them exposed to maximum light again to aid the feeding process.
You are probably are aware of these methods, and don't want to go down that route but you will still need the three principle rules.
1) exclude light from the stem.
2) ensure the leaves are not broken and get maximum light.
3) employ a good feeding regime.
Providing you are growing a ' blanching' variety you should get some quite good results.
I hope that helps!