ては～ては

ては～ては describes two actions that keep following each other in a cycle: A then B, A then B, over and over. The first verb is in the て-form plus は, the second in the ます-stem, and the pair is said twice.

The ます-stem in the second slot is the written style. In speech you also hear the て-form there: かいては書いてはけして消して、かいては書いてはけして消して.

How the cycle ends

After the second pair comes whatever the cycle is in the sentence: の plus a noun such as せいかつ生活 or まいにち毎日, をくりかえす繰り返す, する, or で to give a reason.

Tone

The repetition is usually tiresome: wasted effort, a rut, a cycle that goes nowhere. It can also describe persistence, when the cycle eventually gets somewhere.

ては～ては or たり～たり

たり〜～たり picks out a few things you did, in no set order. ては～ては insists on one pair of actions recurring, in that order.