To use a true peak meter effectively, you need to follow some basic steps. First, you need to insert a true peak meter plugin on your master bus or output channel of your DAW (digital audio workstation) or mastering software. There are many true peak meter plugins available, such as iZotope Insight 2, FabFilter Pro-L 2, or Waves WLM Plus. Make sure that your true peak meter plugin is set to the correct standard and scale for your audio format and target platform. For example, if you are mastering for CD, you may want to use the EBU R128 standard and a -1 dBTP (decibels true peak) scale. If you are mastering for streaming, you may want to use the LUFS (loudness units relative to full scale) standard and a -2 dBTP or -3 dBTP scale. Second, you need to monitor your levels and adjust your gain staging, compression, limiting, and other processing accordingly. Your goal is to achieve a balanced and consistent loudness level for your audio, without exceeding the true peak level that you have set for your format and platform. You can use a loudness meter plugin, such as iZotope Insight 2 or Youlean Loudness Meter, to measure the integrated loudness, short-term loudness, and loudness range of your audio. You can also use a spectrum analyzer plugin, such as iZotope Ozone 9 or FabFilter Pro-Q 3, to check the frequency balance and identify any problematic areas. Third, you need to export your audio file with the proper settings and quality. Make sure that you choose the correct bit depth, sample rate, dithering, and format for your audio file. You can also use a codec preview plugin, such as iZotope RX 8 or Sonnox Codec Toolbox, to listen to how your audio will sound after being converted to different formats, such as MP3 or AAC. This can help you identify any potential issues or artifacts that may occur due to the codec compression.