Info
denotes something to be considered about (...)
にしても
uses Adverbial to denote that "even considering (...), {the opposite/something else}". This makes it very similar to でも
パーティーに行くにしても、私はシャイだからいつも一人で飲んでいる。 even when I do go to a party, I am shy so I always drink alone
独身にしても、家具が少なくない？ even though you are single, isn't this very little furniture?
山で散歩する時は、どこしてもベルを持っていった方がいい。 When you go walking in the mountains, no matter where you go, it's best to bring a bell.
にしては
Again has the notion of 'considering that (...)', and then something that defies expectations. Now however, it is more of surprise at not meeting the expectation
始めたばかりにしては結構じょうずだね。 Considering that he only started recently, he's pretty good!
田舎にしてはコンビニがいっぱいあるね。 Taking into consideration that this is the countryside, there are a lot of konbini!
中卒にしては頭がいいけど、大卒の{同級生|どうきゅうせい}と比べるとそうでもない。
For a middle school graduate, he is smart, but compared to college graduates of the same age he is not the smart.