If you're working with two SSH keys (work / personal) then the following setup is quite elegant. It assumes all repositories are work related, unless they're hosted under your own user:
Host *
```<br></br>```
AddKeysToAgent yes
```<br></br>```
UseKeychain yes
```<br></br>```
StrictHostKeyChecking no
```<br></br>```
User git
```<br></br>```
IdentityFile ~/.ssh/id_rsa_corporate
```<br></br><br></br>```
# personal account
```<br></br>```
Host github.com-MYUSERNAME
```<br></br>```
HostName <a class="c-link" href="https://slack-redir.net/link?url=http%3A%2F%2Fgithub.com&v=3">github.com</a>
```<br></br>```
User git
```<br></br>```
IdentityFile ~/.ssh/id_rsa