You can tie a Running Bowline by tying a Bowline around its own standing part or by tying a Bowline the usual way, and then pulling a bight of the standing part through the loop.
1 Tie the Running Bowline by tying a Bowline around the standing part.
2 The result: Running Bowline.
If you make a fixed-loop knot like the Bowline or any other fixed-loop knot, and decide the loop part is not big enough, just turn it into a running loop knot and have the loop as big as you need it. Because the fixed loop part does not lock onto or grip the standing part, the noose will slide open easily even if great tension is placed on the sliding loop.