I will probably reference an Experimental Physicist to give a better and more detailed answer, however here‘s some of the high notes;

Tracking tiny particles, especially at the microscopic or nanoscopic scale, requires sophisticated techniques that can accurately monitor their position, velocity, and sometimes even orientation over time. The choice of the best tracking method often depends on the specific requirements of the experiment, such as the size of the particles, the environment in which they are being tracked, and the desired spatial and temporal resolution. Here are some of the most commonly used and advanced techniques for tracking tiny particles:

1. Optical Microscopy:

- Bright-field and Dark-field Microscopy: Suitable for particles larger than the wavelength of light, though dark-field can enhance contrast for smaller particles.

- Fluorescence Microscopy: Highly sensitive and specific, capable of tracking fluorescently labeled particles even at the single-molecule level.

- Confocal Microscopy: Offers optical sectioning capabilities to track particles in three dimensions within thick samples.

2. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM): Provide high-resolution images of particles on surfaces (SEM) or in thin samples (TEM), but are generally used for static imaging due to vacuum requirements.

3. Total Internal Reflection Fluorescence (TIRF) Microscopy: Offers near-surface sensitivity, making it ideal for tracking particles or molecules at or near cell membranes.

4. Super-Resolution Microscopy Techniques:

- STORM (Stochastic Optical Reconstruction Microscopy) and PALM (Photoactivated Localization Microscopy): Allow for tracking of particles with nanometer spatial resolution, surpassing the diffraction limit of light.

- Structured Illumination Microscopy (SIM): Increases resolution beyond the diffraction limit by using patterned light, suitable for live-cell imaging.

5. Atomic Force Microscopy (AFM): Can image surfaces at the atomic level and track particles in real-time, though it's more commonly used for static imaging.

6. Particle Tracking Velocimetry (PTV): Used in fluid dynamics to track the motion of particles seeded into flows, allowing the measurement of velocity fields.

7. Digital Holographic Microscopy: Captures 3D images of particles by recording the interference pattern of a light beam scattered by the particle and a reference beam. It's useful for tracking particles in three dimensions without the need for scanning.

8. X-ray Microscopy: Especially useful for tracking particles in dense or opaque materials, with recent advances allowing for nanometer resolution.

9. Nanoparticle Tracking Analysis (NTA): Tracks the Brownian motion of nanoparticles in suspension to determine their size distribution and concentration.

The best choice depends on the specific requirements, including the size of the particles, the environment (in vivo, in vitro, or in materials), and whether dynamic or static information is required. For biological applications, fluorescence-based methods are among the most popular due to their high specificity and sensitivity, while for materials science, electron microscopy and AFM might be more suitable.