You can set number of PHP variables from your cpanel instead of using php_value in .htaccess or using custom php.ini file:
To modify PHP variables, you'll need to select a non-native PHP version from your cPanel. This is because the native PHP version (used by all websites on the server) can't be customized. Choose a non-native PHP version, and then you'll be able to adjust the settings to suit your needs:
Remember that you have to adjust post_max_size to be equal to or bigger than upload_max_filesize, both variables are responsible of files uploading