The method of cutting and slowing down part of the video is as follows:

1. Open the cut and click "Start Creating". After importing the video, slide to the position of the video that needs to be edited and click "Edit". Then click "Split" to divide the parts that need to be slowed down. Select the short video that needs to be slowed down and click "Change Speed" below. Select "Regular Speed", pull the small slider, select a suitable speed, and click the check mark.

2. Open the clipping app software on your mobile phone, then select the video and click the add option. After opening the video, click the speed change option below. Click on the regular speed change, pull the small slider, and select a suitable speed. Open the clip, click "Start Creating", select the required materials, and click "Add".

3. Select the added video material and slide it to the music block in the middle of the video. Click the screen at the playback position, and the clip key icon will pop up. Select the variable speed in the pop-up interface, and the interface options will pop up below. Select regular shifting on the shifting interface, and the shifting slider will pop up. You can adjust the music rhythm by sliding the slider to complete the music rhythm change.

The precautions for editing videos are as follows:

1. Source and processing method of materials: The source of the materials needs to be indicated and relevant laws and regulations must be followed. At the same time, proper processing of the material can better match the editing effect. Rhythm and logic of the editing process: The editing process needs to have a certain sense of rhythm to attract the audience's attention, while maintaining logic so that the entire video clip can be coherent and smooth.

2. Processing of sounds, images, colors, etc.: Sound, images, colors, etc. all need to be properly processed to achieve better results. For example, add sound effects, music, color correction, etc. The presentation and processing of the plot and characters: During the editing process, attention needs to be paid to the presentation and processing of the plot and characters to better present the storyline and characters.

3. Selection and usage skills of editing software: Choosing appropriate editing software can greatly improve editing efficiency and quality. At the same time, mastering some usage skills can better handle video materials. Copyright issues: You need to pay attention to copyright issues and do not infringe other people's intellectual property rights.