事(こと)からFrom the fact that

ことから is used to draw a logical conclusion from a fact or observation, e.g. 顔色が悪いことから風邪を引いていると分かった 'From the fact that his face was pale, I could tell he had caught a cold.' 点 comments on a specific point without implying a conclusion, e.g. 安さという点でこのスマホのほうがいい 'This smartphone is better from the perspective of low price.'

ことから and から言うと both express basis or reasoning, but differ in tone and usage. ことから is generally used for factual inference or deduction, e.g. 電気が付いていないことから、誰もいないと分かった ('Judging from the fact the lights are off, I could tell no one is there'). から言うと provides a basis for a stated opinion, e.g. 経験から言うと注意が必要だ ('Speaking from experience, caution is required').

ことから and からして both express reasoning, but in different ways. ことから means 'from the fact that (A)' and is used to explain a cause or basis, e.g. 声がふるえていることから緊張していると分かる ('From the fact their voice is trembling, I know they're nervous'). からして highlights a telling detail as evidence, e.g. 見た目からして運動していそう ('Judging from her appearance, it looks like she exercises').

ことから and からすると・からすれば both describe drawing conclusions, but differ in tone and focus. ことから shows cause and effect based on a fact, e.g. 足音がしたことから誰かがいると分かる ('From the fact we heard footsteps, we know someone is there'). からすると・からすれば show judgment from a certain viewpoint, e.g. 足音からすると一人の女性だったみたい ('Judging from the footsteps, it seems like it was one woman').

ことから and ことだから both express reasons, but differ in usage. ことから explains a fact-based conclusion, e.g. 顔が赤いことから熱があると分かった ('From the fact their face is red, I knew they had a fever'). ことだから gives a reason based on someone's known traits, e.g. 田中さんのことだから、もう宿題は終わっているだろう ('Since we're talking about Tanaka, he's probably finished his assignment already').