Deponds on your use case. Use groove or curl or etc.... The curl syntax would be [1] replace within anchor accordingly. Example to create a tag Test under default namespace is [2]...
[1] curl --data ":status=browser&_charset_=utf-8&cmd=createTag&jcr:description=<desc>&jcr:title=<title>&parentTagID=<namespace>&tag=<tagname>" http://<host>:<port>/bin/tagcommand
[2]
curl --data ":status=browser&_charset_=utf-8&cmd=createTag&jcr:description=Desc&jcr:title=Title&parentTagID=default:&tag=Test" http://localhost:4502/bin/tagcommand