There are better fillers to use than &quot;um&quot; and &quot;uh&quot;, though, which don&#x27;t reflect as badly on the speaker.  As some random examples, you can connect things with &quot;Now, [pause] ...&quot;, or &quot;On the other hand,&quot; or &quot;For that matter,&quot;, or many other connecting phrases.  Those can be time-fillers too, but as long as they&#x27;re not overused, they just sound like conversational language rather than making the speaker sound awkward or unpracticed.